Segments - Schedule of Company's Segment Results (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenues, net	$ 295,283	$ 225,150	$ 822,693	$ 639,670
Operating income	144,207	111,255	392,827	314,582
Depreciation and amortization	25,714	18,060	74,561	48,579
Capital expenditures	6,727	5,240	18,279	15,348
North America [Member]
Segment Reporting Information [Line Items]
Revenues, net	156,343	115,266	421,579	335,346
Operating income	78,797	59,093	203,311	168,622
Depreciation and amortization	6,635	5,159	19,647	15,598
Capital expenditures	1,561	1,942	5,397	4,298
International [Member]
Segment Reporting Information [Line Items]
Revenues, net	138,940	109,884	401,114	304,324
Operating income	65,410	52,162	189,516	145,960
Depreciation and amortization	19,079	12,901	54,914	32,981
Capital expenditures	$ 5,166	$ 3,298	$ 12,882	$ 11,050