Selected Financial Information by Reportable Operating Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Revenues	$ 725,622	$ 649,606	$ 1,273,395	$ 1,228,424
Adjusted EBITDA	178,024	156,952	294,280	297,280
Capital expenditures	53,499	46,603	90,388	93,587
U.S.
Segment Reporting Information [Line Items]
Revenues	517,109	443,765	883,472	854,990
Adjusted EBITDA	128,697	103,391	208,775	207,684
Capital expenditures	29,631	27,109	35,787	46,803
International
Segment Reporting Information [Line Items]
Revenues	211,879	208,372	396,072	378,247
Adjusted EBITDA	49,327	53,561	85,505	89,596
Capital expenditures	23,868	19,494	54,601	46,784
Eliminations
Segment Reporting Information [Line Items]
Revenues	$ (3,366)	$ (2,531)	$ (6,149)	$ (4,813)