Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets:
Restricted cash	$ 10	$ 10
Liabilities:
Contingent consideration	46,600	45,100
Unobservable Inputs (Level 3)
Liabilities:
Contingent consideration	46,600
Recurring
Assets:
Cash and cash equivalents	20,268	25,342
Restricted cash	10	10
Total assets	20,278	25,352
Liabilities:
Warrant liability	2	5
Contingent consideration	46,600	45,100
Total liabilities	46,602	45,105
Recurring | Active Markets (Level 1)
Assets:
Cash and cash equivalents	20,268	25,342
Restricted cash	10	10
Total assets	20,278	25,352
Liabilities:
Warrant liability	0	0
Contingent consideration	0	0
Total liabilities	0	0
Recurring | Observable Inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Total assets	0	0
Liabilities:
Warrant liability	0	0
Contingent consideration	0	0
Total liabilities	0	0
Recurring | Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Total assets	0	0
Liabilities:
Warrant liability	2	5
Contingent consideration	46,600	45,100
Total liabilities	$ 46,602	$ 45,105