Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	$ 634,482	$ 563,405
Accumulated Amortization	(118,780)	(99,541)
Net Carrying Amount	515,702	463,864
Customer and Vendor Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	555,078	487,718
Accumulated Amortization	(108,662)	(90,920)
Net Carrying Amount	446,416	396,798
Customer and Vendor Agreements [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	3 years	3 years
Customer and Vendor Agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	20 years	20 years
Trade Names and Trademarks-Indefinite Lived [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	56,532	53,926
Net Carrying Amount	56,532	53,926
Trade Names and Trademarks-Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	3,340	3,160
Accumulated Amortization	(1,528)	(1,420)
Net Carrying Amount	1,812	1,740
Trade Names and Trademarks-Other [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	3 years	3 years
Trade Names and Trademarks-Other [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	15 years	15 years
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	16,261	15,330
Accumulated Amortization	(6,271)	(5,208)
Net Carrying Amount	9,990	10,122
Software [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	3 years	3 years
Software [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	10 years	10 years
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amounts	3,271	3,271
Accumulated Amortization	(2,319)	(1,993)
Net Carrying Amount	$ 952	$ 1,278
Non-compete Agreements [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	2 years	2 years
Non-compete Agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Lives (Years)	6 years	6 years