Selected Financial Information by Reportable Operating Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Revenues	$ 757,566	$ 633,573	$ 2,030,961	$ 1,861,997
Adjusted EBITDA	190,173	148,370	484,453	445,650
Capital expenditures	69,100	52,940	159,488	146,527
U.S. Operating Segment
Segment Reporting Information [Line Items]
Revenues	529,426	416,165	1,412,898	1,271,155
Adjusted EBITDA	132,803	94,538	341,579	302,222
Capital expenditures	35,746	27,357	71,533	74,160
International Segment
Segment Reporting Information [Line Items]
Revenues	231,771	220,633	627,843	598,880
Adjusted EBITDA	57,370	53,832	142,874	143,428
Capital expenditures	33,354	25,583	87,955	72,367
Eliminations
Segment Reporting Information [Line Items]
Revenues	$ (3,631)	$ (3,225)	$ (9,780)	$ (8,038)