Subsequent Event - Pending Merger with Laborie Medical Technologies (Details) - Subsequent Event [Member] $ / shares in Units, $ in Millions	Mar. 12, 2018 USD ($) $ / shares
Subsequent Event [Line Items]
Consideration in definitive merger agreement \| $	$ 239
Tender offer for common stock in cash (in dollars per share) \| $ / shares	$ 3.85
Percentage of premium over average closing stock price	28.00%
Period prior to definitive merger agreement	30 days

Amount of consideration to be paid under definitive merger agreement.

No definition available.

Name:	cgnt_ConsiderationDefinitiveMergerAgreement
Namespace Prefix:	cgnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Refers to the percentage of premium over the average closing stock price of last thirty days prior to entering into the agreement.

+ References

No definition available.

+ Details

Name:	cgnt_PercentageOfPremiumOverAverageClosingStockPrice
Namespace Prefix:	cgnt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time prior to the definitive merger agreement used to determine premium over the average closing stock price of the company's common stock paid for outstanding shares of the company's common stock in tender offer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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No definition available.

+ Details

Name:	cgnt_PeriodPriorToDefinitiveMergerAgreement
Namespace Prefix:	cgnt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Tender offer for common stock in cash under definitive merger agreement.

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No definition available.

+ Details

Name:	cgnt_TenderOfferForCommonStock
Namespace Prefix:	cgnt_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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No definition available.

+ Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: