Segments (Schedule Of Company's Segment Results) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Segment Reporting Information [Line Items]
Revenues, net	$ 171,820	$ 134,213	$ 317,985	$ 245,218
Operating income	81,448	59,892	145,923	110,379
Depreciation and amortization	11,609	8,588	23,329	17,195
Capital expenditures	4,868	3,322	8,431	5,916
North America [Member]
Segment Reporting Information [Line Items]
Revenues, net	107,286	92,865	190,098	164,449
Operating income	53,598	40,471	91,711	71,990
Depreciation and amortization	5,024	4,889	10,018	9,831
Capital expenditures	2,501	1,347	4,596	2,834
International [Member]
Segment Reporting Information [Line Items]
Revenues, net	64,534	41,348	127,887	80,769
Operating income	27,850	19,421	54,212	38,389
Depreciation and amortization	6,585	3,699	13,311	7,364
Capital expenditures	$ 2,367	$ 1,975	$ 3,835	$ 3,082