Document And Entity Information us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears Year 4 Note To Financial Statement Details Textual statementsignificantaccountingpoliciespolicies statementnote2inventoriestables us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears Year 5 statementnote3equipmentandleaseholdimprovementsnettables us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears Year 2 Customer Number 3 [Member] Information pertaining to customer number 3 accounting for a percentage of accounts receivable. statementnote5accruedexpensestables statementnote6longtermdebttables statementnote7operatingleasestables us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears Year 3 us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Payments in stock withheld for tax payment on issuance Variable Rate [Domain] statementnote9sharebasedcompensationtables OPERATING EXPENSES: Variable Rate [Axis] statementnote11earningslosspersharetables Prime Rate [Member] us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent Next 12 Months statementnote2inventoriescomponentsofinventorydetails statementnote3equipmentandleaseholdimprovementsnetestimatedusefullivesdetails us-gaap_LongTermDebt Long-term Debt statementnote3equipmentandleaseholdimprovementsnetcomponentsofequipmentandleaseholdimprovementsdetails statementnote5accruedexpensescomponentsofaccruedexpensesdetails statementnote6longtermdebtsummaryoflongtermdebtdetails us-gaap_CapitalLeaseObligations Capital Lease Obligations Schedule of Long-term Debt Instruments [Table Text Block] statementnote6longtermdebtfuturepaymentsdetails statementnote7operatingleasessummaryoffutureminimumleasepaymentsundernoncancelableoperatingleasesdetails statementnote9sharebasedcompensationsharesauthorizedavailableforfuturegrantandoutstandingundereachplandetails statementnote9sharebasedcompensationsummaryofoptionactivityunderstockplansdetails statementnote9sharebasedcompensationsummaryofnonvestedoptionsdetails statementnote9sharebasedcompensationsummaryoftheweightedaveragecharacteristicsofoutstandingstockoptionsdetails statementnote9sharebasedcompensationsummaryofvaluationassumptionsrelatedtooptionsgranteddetails statementnote9sharebasedcompensationrestrictedstockunitsdetails statementnote11earningslosspersharesummaryofreconciliationsbetweenthenumeratorandthedenominatorofthebasicanddilutedearningspersharecomputationsdetails Notes To Financial Statements Notes To Financial Statements [Abstract] CASH FLOWS FROM INVESTING ACTIVITIES: Proceeds from stock options exercised cyan_LongTermDebtAndCapitalLeaseObligationsCurrentAndNoncurrent Long-term Debt and Capital Lease Obligations, Current and Noncurrent Sum of the carrying values as of the balance sheet date of both current and noncurrent portions of long-term debt and capital lease obligations. Lease Arrangement, Type [Axis] Long-term Debt [Text Block] us-gaap_DeferredFinanceCostsNet Less unamortized debt issuance costs Equity Component [Domain] 2014 Directors Plan [Member] Represents the "2014 Directors Plan." Lease Arrangement, Type [Domain] The 2005 Plan [Member] Represents the "2005 Plan." Leases of Lessee Disclosure [Text Block] cyan_CurrentRatio Current Ratio Current assets divided by current liabilities, expressed as a ratio. 2004 Directors Plan [Member] Represents the "2004 Directors Plan." Equity Components [Axis] cyan_DebtCovenantMinimumCurrentRatio Debt Covenant, Minimum Current Ratio The minimum current ratio (current assets divided by current liabilities, expressed as a ratio) as required under a debt covenant. us-gaap_IncreaseDecreaseInCustomerDeposits Customer deposits Property, Plant, and Equipment, Estimated Useful Lives [Table Text Block] Tabular disclosure of the useful life of long lived, physical assets used in the normal conduct of business and not intended for resale. us-gaap_IncreaseDecreaseInAccruedLiabilities Accrued expenses us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity Line of Credit Facility, Remaining Borrowing Capacity Preferred outstanding, shares (in shares) Common stock, shares outstanding (in shares) us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Rent and utilities Carrying value as of the balance sheet date of obligations incurred through that date and payable for contractual rent under lease arrangements and utilities, such as electrical power, heating oil, natural gas, and water. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). New Accounting Pronouncements, Policy [Policy Text Block] Reclassification, Policy [Policy Text Block] us-gaap_LongTermDebtAndCapitalLeaseObligationsIncludingCurrentMaturities Total principal payments Diluted (in shares) Shares outstanding - diluted (in shares) us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount us-gaap_LongTermDebtAndCapitalLeaseObligations Long-term debt, excluding current maturities us-gaap_IncreaseDecreaseInAccountsPayable Accounts payable us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted Shares outstanding - basic and diluted (in shares) us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment Shares - dilutive securities (in shares) Capital Lease Asses Payable in 36 Equal Monthly Payments [Member] Represents information regarding to capital lease assets which are payable in 36 equal payments. Year 5 us-gaap_EarningsPerShareBasicAndDiluted Earnings per share - basic and diluted (in dollars per share) The 2016 Plan [Member] Represents the 2016 Cyanotech Equity Incentive Plan (the “2016 Plan”). Year 4 us-gaap_SharePrice Share Price Thereafter Year 3 Subsequent Event [Member] cyan_SharebasedCompensationArrangementBySharebasedPaymentAwardNumberOfSharesAuthorizedForIssuanceInConnectionWithPerformanceAwardsAndStockAwards Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized for Issuance in Connection with Performance Awards and Stock Awards The maximum number of shares (or other type of equity) originally approved to be issued in connection with performance awards and stock awards (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). Year 2 Line of Credit Facility, Lender [Domain] Next 12 Months Diluted (in dollars per share) Earnings per share - diluted (in dollars per share) Lender Name [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Axis] us-gaap_SalesRevenueNet NET SALES Cash Cash and Cash Equivalents, at Carrying Value Cash at beginning of period Cash at end of period us-gaap_RepaymentsOfLongTermCapitalLeaseObligations Payments on capitalized leases us-gaap_RepaymentsOfLongTermDebt Principal payments on long-term debt Equipment [Member] Long-term debt, less current maturities Total long-term debt, net of current maturities and unamortized debt issuance costs Amount of long-term debt and capital lease obligation net of issuance costs, due after one year or beyond the normal operating cycle, if longer. Basic (in shares) Shares outstanding - basic (in shares) Basic (in dollars per share) Earnings per share - basic (in dollars per share) Scenario, Unspecified [Domain] Scenario, Forecast [Member] Deferred rent and other liabilities Scenario [Axis] Short-term Debt [Text Block] Schedule of Accrued Liabilities [Table Text Block] us-gaap_ProceedsFromIssuanceOfLongTermDebt Proceeds from Issuance of Long-term Debt us-gaap_ConcentrationRiskPercentage1 Concentration Risk, Percentage Maximum [Member] Customer Concentration Risk [Member] Range [Domain] Minimum [Member] Customer [Axis] Concentration Risk Type [Domain] Range [Axis] us-gaap_UnrecognizedTaxBenefits Unrecognized Tax Benefits Customer [Domain] Accounting Policies [Abstract] Net increase (decrease) in liabilities: Statement of Financial Position [Abstract] Relationship to Entity [Domain] Concentration Risk Type [Axis] Title of Individual [Axis] us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other assets Bank of the West Finance [Member] Finance agreements with Bank of the West. Sales Revenue, Net [Member] Statement of Cash Flows [Abstract] Accounts Receivable [Member] us-gaap_RepaymentsOfNotesPayable Payment of short term notes payable Equipment Finance Agreement [Member] A financing agreement that allows for the purchase of equipment by the reporting entity. Proceeds from short term note payable cyan_DebtAgreementMaximumBorrowingCapacity Debt Agreement, Maximum Borrowing Capacity Maximum borrowing capacity under a debt agreement on the amount that could be borrowed with a combination of, but not limited to, a line of credit and term loan. us-gaap_AllocatedShareBasedCompensationExpense Allocated Share-based Compensation Expense Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Axis] Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised Exercised (in shares) First Foundation Bank [Member] Represents information about First Foundation Bank. Net (payments) draws on line of credit us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod Forfeited (in shares) Granted (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross Granted (in shares) us-gaap_InterestIncomeExpenseNonoperatingNet Interest expense, net us-gaap_ProceedsFromIssuanceOfDebt Proceeds from Issuance of Debt us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity INCOME TAX EXPENSE (BENEFIT) Income Tax Expense (Benefit) us-gaap_EffectiveIncomeTaxRateContinuingOperations Effective Income Tax Rate Reconciliation, Percent Accumulated deficit us-gaap_PolicyTextBlockAbstract Accounting Policies us-gaap_IncreaseDecreaseInInventories Inventories Accounts Payable and Accrued Liabilities Disclosure [Text Block] Credit Facility [Domain] Statement [Table] Revolving Credit Facility [Member] Credit Facility [Axis] Income Statement [Abstract] CASH FLOWS FROM FINANCING ACTIVITIES: Class of Stock [Axis] Award Type [Axis] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Other long-term liabilities Equity Award [Domain] Segment Reporting Disclosure [Text Block] us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Prepaid expenses and other current assets us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements The 2015 Loan Agreement [Member] Represents the 2015 Loan Agreement with a lender. us-gaap_CustomerDepositsCurrent Customer deposits us-gaap_LiabilitiesCurrent Total current liabilities Schedule of Maturities of Long-term Debt [Table Text Block] Raw materials Supplies Exercisable Options Number of Shares (in shares) Finished goods (1) Outstanding Options Remaining Life (Year) Exercisable Options Weighted Average Price (in dollars per share) Work in process us-gaap_OperatingExpenses Total operating expenses Outstanding Options Weighted Average Price (in dollars per share) Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Outstanding Options Number of Shares (in shares) Net (increase) decrease in assets: Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Stock Options, Activity [Table Text Block] Upper Range of Exercise (in dollars per share) Lower Range of Exercise (in dollars per share) General and administrative Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] Property, Plant and Equipment [Table Text Block] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice Exercise Price (in dollars per share) Exercise Price Range [Axis] Property, Plant and Equipment Disclosure [Text Block] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate Dividend Rate Schedule of Nonvested Share Activity [Table Text Block] Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate Risk Free Rate us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate Volatility us-gaap_OperatingIncomeLoss Income (loss) from operations Schedule of Inventory, Current [Table Text Block] Inventory Disclosure [Text Block] us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1 Expected Life (in years) (Year) us-gaap_GrossProfit Gross profit Current maturities of long-term debt Less current maturities Amendment Flag Common stock of $0.02 par value, shares authorized 50,000,000; 5,743,882 shares issued and outstanding at September 30, 2017 and 5,685,381 shares at March 31, 2017 Commitments and Contingencies Disclosure [Text Block] Forfeited, weighted average grant price (in dollars per share) Common stock, shares authorized (in shares) Vested, weighted average grant price (in dollars per share) Common stock, shares issued (in shares) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue Nonvested restricted stock units at March 31, 2016, weighted average grant price (in dollars per share) Nonvested restricted stock units at March 31, 2017, weighted average grant price (in dollars per share) Other assets us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber Outstanding (in shares) Nonvested restricted stock units at March 31, 2017 (in shares) Nonvested restricted stock units at September 30, 2017 (in shares) Common stock, par value (in dollars per share) Income Tax Disclosure [Text Block] Granted, weighted average grant price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Share-based compensation expense Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod Forfeited (in shares) Current Fiscal Year End Date Line of credit Line of Credit, Current Vested (in shares) us-gaap_CapitalLeasedAssetsNumberOfUnits Capital Leased Assets, Number of Units Document Fiscal Period Focus Document Fiscal Year Focus us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1 Exercisable, aggregate intrinsic value us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1 Exercisable, weighted average remaining contractual term (Year) Document Period End Date us-gaap_AssetImpairmentCharges Asset Impairment Charges Preferred stock of $0.01 par value, authorized 10,000,000 shares; no shares issued and outstanding Preferred, issued shares (in shares) Chief Executive Officer [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice Exercisable, weighted average exercise price (in dollars per share) Document Type us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber Exercisable (in shares) Customer Number 1 [Member] Information pertaining to customer number 1 accounting for a percentage of accounts receivable. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue Outstanding, aggregate intrinsic value us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2 Outstanding, weighted average remaining contractual term (Year) Depreciation and amortization Preferred, authorized shares (in shares) Customer Number 2 [Member] Information pertaining to customer number 2 accounting for a percentage of accounts receivable. Granted (in dollars per share) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue Forfeited (in dollars per share) Accounts payable Document Information [Line Items] us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue Vested (in dollars per share) Document Information [Table] Preferred stock, par value (in dollars per share) us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue Nonvested (in dollars per share) Nonvested (in dollars per share) us-gaap_AssetsCurrent Total current assets Accrued expenses Total accrued expenses Entity Filer Category us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares Forfeited (in shares) Entity Current Reporting Status Counterparty Name [Domain] Entity Voluntary Filers Counterparty Name [Axis] us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares Nonvested (in shares) Nonvested (in shares) Entity Well-known Seasoned Issuer us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice Outstanding, weighted average exercise price (in dollars per share) Outstanding, weighted average exercise price (in dollars per share) Employees [Member] Refers to information regarding employees. us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares Vested (in shares) us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice Forfeited, weighted average exercise price (in dollars per share) Wages, commissions, bonus and profit sharing Exercised (in shares) The number of equity-based payment instruments, excluding stock (or unit) options, that were exercised during the reporting period. Exercised, weighted average grant price (in dollars per share) Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were exercised. us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice Granted, weighted average exercise price (in dollars per share) us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice Exercised, weighted average exercise price (in dollars per share) Other accrued expenses cyan_NonInventoriableFixedCosts Non Inventoriable Fixed Costs Represents the non-inventoriable fixed costs incurred during the period. Adjustments to reconcile net income (loss) to net cash provided by operating activities: Entity Central Index Key Entity Registrant Name Term Loan Agreement, Maturing on August 14, 2032 [Member] Represents the term loan agreement that are maturing on august 14, 2032. Entity [Domain] Term Loan Agreement, Promissory Note One [Member] Term loan agreement, promissory note one [member] SHARES USED IN CALCULATION OF NET INCOME (LOSS) PER SHARE: Legal Entity [Axis] Term Loan Agreement, Promissory Note Two [Member] Term loan agreement, promissory note two [member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Outstanding (in shares) Outstanding (in shares) Outstanding (in shares) cyan_DebtInstrumentInterestPaymentPeriod Debt Instrument Interest Payment Period Represents the period for which interest is payable. cyan_DebtInstrumentAmortizationPeriod Debt Instrument Amortization Period Represents the period over which obligation under the debt instrument fully amortizes. Liquidity and Debt Covenant Compliance [Policy Text Block] Disclosure of accounting policy for liquidity and debt covenant compliance. cyan_DebtInstrumentReferenceRate Debt Instrument Reference Rate Represents the reference rate used to compute the variable rate on the debt instrument. cyan_DebtInstrumentPrepaymentPenaltyPercentage Debt Instrument, Prepayment Penalty Percentage Represents the prepayment penalty rate applicable, if any prepayment is made prior to the first anniversary. cyan_DebtInstrumentPrepaymentPenaltyPercentageReductionDuringEachYear Debt Instrument, Prepayment Penalty Percentage Reduction During Each Year Represents the percentage of reduction in prepayment penalty rate each year. cyan_NumberOfMajorCustomers Number of Major Customers Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc cyan_WorkingCapitalDeficit Working Capital (Deficit) The difference between the current assets and current liabilities that is used as a financial metric for operating liquidity. cyan_DebtInstrumentOneTimeOriginationAndGuarantyFees Debt Instrument One Time Origination and Guaranty Fees Amount of one-time origination and guaranty fees on the debt instrument. cyan_DebtInstrumentAnnualRenewalFeePayablePercentage Debt Instrument Annual Renewal Fee Payable Percentage Represents the percentage of annual renewal fee payable on the debt instrument. cyan_DebtInstrumentGuaranteedPortion Debt Instrument Guaranteed Portion Represents the guaranteed portion of the debt instrument. cyan_DebtInstrumentPeriodicPaymentsNumber Debt Instrument Periodic Payments Number Represents the number of required periodic payments. Current liabilities: Entity Common Stock, Shares Outstanding (in shares) Available (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Additional paid-in capital Interest us-gaap_Assets Total assets Effect of dilutive securities on net income Inventories, net Inventories, net Stockholders’ equity: Authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period us-gaap_PaymentsToAcquireProductiveAssets Investment in equipment and leasehold improvements Trading Symbol us-gaap_InventoryValuationReserves Inventory Valuation Reserves cyan_ShareBasedCompensationArrangementBySharebasedPaymentAwardOptionsAndNonOptionEquityInstrumentsOutstandingNumber Outstanding (in shares) Number of non-option equity instruments and options outstanding, including both vested and non-vested instruments. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period us-gaap_GainLossOnDispositionOfAssets Loss (gain) on disposal of assets Net income (loss) NET INCOME (LOSS) Schedule of Share-based Compensation Shares Authorized Available and Outstanding by Plan [Table Text Block] Tabular disclosure of shares authorized, available for future grant and outstanding under each stock-based compensation plan. us-gaap_StockholdersEquity Total stockholders’ equity Plan Name [Axis] us-gaap_DebtInstrumentTerm Debt Instrument, Term Plan Name [Domain] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Commitments and contingencies us-gaap_Liabilities Total liabilities us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Sales and marketing Range 01 [Member] Range 1 in a range of exercise prices. Restricted Stock Units (RSUs) [Member] Range 02 [Member] Range 2 in a range of exercise prices. COST OF SALES Range 03 [Member] Range 03 [member] Restricted Stock [Member] Range 04 [Member] Range 04 [member] Antidilutive Securities, Name [Domain] Employee Stock Option [Member] CASH FLOWS FROM OPERATING ACTIVITIES: Accounts receivable, allowance for doubtful accounts Antidilutive Securities [Axis] Accounts receivable, net of allowance for doubtful accounts of $27 at September 30, 2017 and $49 at March 31, 2017 Statement [Line Items] Research and development cyan_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsVestingPeriod Vesting Period (years) (Year) Vesting period of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Disclosure of Compensation Related Costs, Share-based Payments [Text Block] cyan_ShareasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate Forfeiture Rate The estimated measure of the percentage by which shares under options are expected to be cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. cyan_NumberOfShareholderApprovedSharebasedCompensationPlans Number of Shareholder Approved Share-based Compensation Plans Represents the number of shareholder approved plans under which shares were available for equity based awards. SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION: Income taxes Estimated useful lives (Year) Amortization of debt issue costs and other assets Current assets: us-gaap_PropertyPlantAndEquipmentNet Equipment and leasehold improvements, net Equipment and leasehold improvements, net Net income - diluted us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Less accumulated depreciation and amortization Equipment and leasehold improvements, gross Debt Instrument [Axis] Construction-in-progress Furniture and Fixtures [Member] us-gaap_CapitalLeasedAssetsGross Capital Leased Assets, Gross Debt Instrument, Name [Domain] us-gaap_DebtInstrumentInterestRateDuringPeriod Debt Instrument, Interest Rate During Period us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate us-gaap_DebtInstrumentInterestRateStatedPercentage Debt Instrument, Interest Rate, Stated Percentage Leasehold Improvements [Member] us-gaap_TableTextBlock Notes Tables Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Axis] us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Income (loss) before income taxes us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations Net cash (used in) provided by financing activities us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations Net cash used in investing activities us-gaap_NetCashProvidedByUsedInContinuingOperations Net increase in cash us-gaap_OperatingLeasesFutureMinimumPaymentsDue Total minimum lease payments us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter Thereafter Earnings Per Share [Text Block] us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations Net cash provided by operating activities NET INCOME (LOSS) PER SHARE: