Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Taxes calculated at federal rate	$ 151,468	$ 122,696	$ 108,748
State taxes, net of federal benefit	4,581	2,891	11,480
Change in liability for tax positions	1,094	412	3,537
Foreign income taxed at different rates	(7,111)	(6,091)	8,567
Foreign tax credits	(1,710)	(2,184)	(5,640)
Other items, net	(4,427)	(1,379)	(3,048)
Income tax	$ 143,895	$ 116,345	$ 123,644
Federal income tax rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	1.10%	0.80%	3.70%
Change in liability for tax positions	0.30%	0.10%	1.10%
Foreign income taxed at different rates	(1.60%)	(1.70%)	2.80%
Foreign tax credits	(0.40%)	(0.60%)	(1.80%)
Other items, net	(1.10%)	(0.40%)	(1.00%)
Total	33.30%	33.20%	39.80%