Income Taxes - Schedule of Income Before Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest [Abstract]
U.S.									$ 131,898	$ 129,045	$ 104,881
Foreign									146	80	(186)
Income before provision for income taxes	$ 39,310	$ 35,495	$ 30,625	$ 26,614	$ 35,454	$ 43,455	$ 25,965	$ 24,251	$ 132,044	$ 129,125	$ 104,695