Fair Value - Summary of Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Assets measured at fair value
Cash and cash equivalents	$ 53,511	$ 38,449	$ 28,376	$ 34,766
Total Assets measured at fair value	53,511	38,449
Liabilities measured at fair value
Liabilities measured at fair value Contingent consideration	24,356	23,500
Total liabilities measured at fair value	24,356	23,500
Liabilities measured at fair value Contingent consideration	24,356	23,500
Total liabilities measured at fair value	24,356	23,500
Fair Value, Inputs, Level 1 [Member]
Assets measured at fair value
Cash and cash equivalents	53,511	38,449
Total Assets measured at fair value	53,511	38,449
Fair Value, Inputs, Level 3 [Member]
Liabilities measured at fair value
Liabilities measured at fair value Contingent consideration	24,356	23,500
Total liabilities measured at fair value	24,356	23,500
Liabilities measured at fair value Contingent consideration	24,356	23,500
Total liabilities measured at fair value	$ 24,356	$ 23,500