Accrued expenses and other current liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Employee compensation	$ 11,296	$ 5,935
Accrued goods and services	34,275	15,876
Accrued license and milestone fees	2,464	277
Accrued professional fees	1,492	1,014
Deferred rent, current portion	11	964
Contingent consideration, current portion	4,479	3,584
Other	643	495
Total accrued expenses and other current liabilities	$ 54,660	$ 28,145