v2.4.1.9

Stock Incentive Plans - Summary of Stock-Based Compensation Expense Related to Stock Options Included in Statements of Operations and Comprehensive Loss (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation, Total expensed	$ 535,000us-gaap_AllocatedShareBasedCompensationExpense	$ 72,000us-gaap_AllocatedShareBasedCompensationExpense	$ 69,000us-gaap_AllocatedShareBasedCompensationExpense
Cost of testing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation, Total expensed	28,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_CostOfSalesMember	3,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_CostOfSalesMember	2,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_CostOfSalesMember
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation, Total expensed	88,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_ResearchAndDevelopmentExpenseMember	7,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_ResearchAndDevelopmentExpenseMember	13,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_ResearchAndDevelopmentExpenseMember
Sales and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation, Total expensed	29,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingAndMarketingExpenseMember	3,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingAndMarketingExpenseMember	5,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_SellingAndMarketingExpenseMember
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation, Total expensed	$ 390,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_GeneralAndAdministrativeExpenseMember	$ 59,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_GeneralAndAdministrativeExpenseMember	$ 49,000us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_IncomeStatementLocationAxis = us-gaap_GeneralAndAdministrativeExpenseMember

X

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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

X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_ResearchAndDevelopmentExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SellingAndMarketingExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: