Other Current and Non-Current Liabilities - Schedule of Other Non-Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Other Liabilities Noncurrent [Abstract]
Contingent consideration obligation	$ 144,200	$ 31,700
Accrued payable from acquisitions	30,000
Accrued restructuring liability		7,613
Uncertain tax positions liability, including interest and penalties	10,424	10,065
Other non-current liabilities	2,588	3,208
Total other non-current liabilities	$ 187,212	$ 52,586