Summary of Significant Accounting Policies- Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Significant Accounting Policies [Line Items]
Deferred revenue	$ 2,500,000	$ 3,200,000
Sales commissions	$ 225,000	302,000
Percentage of cash discount offered to customers	2.00%
Deferred tax assets, valuation allowance	$ 36,388,000	33,455,000
Impairment of Intangible Assets, Finite-lived		66,000
ABG [Member]
Significant Accounting Policies [Line Items]
Purchase Order Placed	3,300,000
Genetic Test Revenue [Member]
Significant Accounting Policies [Line Items]
Breakage Revenue	191,000	$ 218,000
Customer Payment [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	150,000
Kits Components [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	2,400,000
Distributors [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	$ 2,300,000