Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 11,832	$ 9,300	$ 8,256
Additions based on tax positions related to the current year	3,224	1,354	1,061
Additions for tax positions of prior years	593	1,624	233
Reductions for tax positions of prior years	(174)	(148)	(192)
Settlement of tax audits	(7)	0	(33)
Unrecognized Tax Benefits, Increase Resulting from Acquisition	11,006	0	0
Reductions due to lapsed statute of limitations	(481)	(298)	(25)
Balance at December 31	$ 25,993	$ 11,832	$ 9,300