Summary of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ (2,429)	$ 30,324	$ 21,363
State and local	1,718	3,296	2,900
Foreign	59	108	284
Current income tax expense, total	(652)	33,728	24,547
Deferred
Federal	(46,247)	11,981	16,538
State and local	2,686	971	(346)
Foreign	(3)	(64)	(106)
Deferred income tax expense, total	(43,564)	12,888	16,086
Total provision	$ (44,216)	$ 46,616	$ 40,633