Income Taxes - Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal
Current									$ 6,545	$ 2,586	$ 14,108
Deferred									(6,587)	19,212	19,034
Total									(42)	21,798	33,142
State
Current									4,441	(1,857)	12,565
Deferred									(2,649)	(1,324)	(2,502)
Total									1,792	(3,181)	10,063
Foreign
Current									17,626	16,048	11,671
Deferred									3,502	3,772	1,170
Total									21,128	19,820	12,841
Income tax provision	$ 21,054	$ 2,012	$ 3,764	$ (3,952)	$ 65,758	$ (2,233)	$ (20,914)	$ (4,174)	$ 22,878	$ 38,437	$ 56,046