Selected Financial Information by Reportable Operating Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 602,280	$ 547,773
Adjusted EBITDA	128,555	116,256
Capital expenditures	52,806	36,889
U.S. Operating Segment
Segment Reporting Information [Line Items]
Revenues	444,920	366,363
Adjusted EBITDA	93,540	80,078
Capital expenditures	30,312	6,156
International Segment
Segment Reporting Information [Line Items]
Revenues	160,192	184,193
Adjusted EBITDA	35,015	36,178
Capital expenditures	22,494	30,733
Eliminations
Segment Reporting Information [Line Items]
Revenues	$ (2,832)	$ (2,783)