Accrued and Other Liabilities - Components of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Debt financing fees	$ 1,747	$ 0
Private Placement and Subsequent Financing offering costs	339	0
Transaction related fees	353	589
Software implementation costs	315	0
Accrued interest payable on debt	762	0
Tax, audit and compliance related fees	370	89
Test sample processing fees	478	426
Accrued overpayments and refunds	339	163
Clinical studies	1,079	756
Deferred rent – current portion	364	258
Capital leases – current portion	53	71
Other accrued expenses	1,496	540
Total accrued and other liabilities	$ 7,695	$ 2,892