Income Taxes - Summary of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
U.S. federal	$ 62,746	$ 27,299	$ 18,550
U.S. state and local	656	7,991	6,799
Foreign	26,644	22,249	(457)
UBT	3,451	2,942	1,944
Provision for income taxes, Current	93,497	60,481	26,836
Deferred:
U.S. federal	(44,562)	76,539	(22,670)
U.S. state and local	8,097	(25,118)	(8,350)
Foreign	4,694	10,549	7,360
UBT	(1,474)	(1,955)	(2,525)
Provision for income taxes, Deferred	(33,245)	60,015	(26,185)
Provision for income taxes	$ 60,252	$ 120,496	$ 651