Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized Income Tax Benefit [Roll Forward]
Beginning balance, unrecognized tax benefits	$ 34,152	$ 31,558	$ 26,155
Additions based on tax provisions related to the current year	4,284	3,755	4,143
Additions for tax positions due to acquisitions			9,208
Deductions based on settlement/expiration of prior year tax positions	(7,342)	(4,161)	(9,119)
Additions based on tax provisions related to the prior year	11,679	3,000	1,171
Ending balance, unrecognized tax benefits	$ 42,773	$ 34,152	$ 31,558