Quarterly Financial Information (Unaudited) - Schedule of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 388,248	$ 304,392	$ 314,438	$ 341,145	$ 375,254	$ 351,014	$ 349,675	$ 326,038	$ 1,348,223	$ 1,401,981	$ 1,358,104
Gross profit	159,272	132,232	141,585	157,359	166,845	158,701	161,084	149,982	590,448	636,612	611,863
Net income	$ 12,338	$ 28,034	$ 36,055	$ 43,674	$ 31,163	$ 42,239	$ 39,806	$ 23,232	$ 120,101	$ 136,440	$ 124,150
Basic (dollars per share)	$ 0.32	$ 0.72	$ 0.93	$ 1.12	$ 0.80	$ 1.09	$ 1.03	$ 0.60	$ 3.09	$ 3.52	$ 3.23
Diluted (dollars per share)	$ 0.31	$ 0.71	$ 0.92	$ 1.11	$ 0.79	$ 1.08	$ 1.01	$ 0.59	$ 3.05	$ 3.48	$ 3.18