Income Taxes - Reconciliation of the Provision for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Income tax expense at the federal statutory rate of 35%	$ 99,646	$ 98,691	$ 95,163
Foreign rate differential	(41,487)	(25,069)	(15,319)
State income taxes, net of effect of federal tax benefit	8,339	5,581	4,240
Unrecognized tax benefits and related interest	9,307	4,853	2,570
Non-deductible transaction costs	253		2,426
Change in valuation allowance	1,999	2,535	3,451
Other, net	1,202	796	1,572
Provision for income taxes	$ 79,259	$ 87,387	$ 94,103