Breakdown of Selected Financial Information by Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 547,773	$ 578,818
Adjusted EBITDA	116,256	140,328
Capital expenditures	36,889	46,984
U.S.
Segment Reporting Information [Line Items]
Revenues	366,363	411,225
Adjusted EBITDA	80,078	104,293
Capital expenditures	6,156	19,694
International
Segment Reporting Information [Line Items]
Revenues	184,193	169,875
Adjusted EBITDA	36,178	36,035
Capital expenditures	30,733	27,290
Eliminations
Segment Reporting Information [Line Items]
Revenues	$ (2,783)	$ (2,282)