Intangibles, Net - Intangibles, Net with Finite Lives (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Carrying Amount	$ 22,743,000	$ 22,743,000
Accumulated Amortization	8,310,000	5,386,000
Total future amortization expense	14,433,000	17,357,000
Customer contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Carrying Amount	5,276,000	5,276,000
Accumulated Amortization	2,593,000	1,322,000
Total future amortization expense	2,683,000	3,954,000
Customer contracts [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	4 years
Customer contracts [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	1 year
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Carrying Amount	13,792,000	13,792,000
Accumulated Amortization	4,458,000	3,398,000
Total future amortization expense	9,334,000	10,394,000
Customer Relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	10 years
Customer Relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	7 years
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years
Carrying Amount	2,585,000	2,585,000
Accumulated Amortization	833,000	445,000
Total future amortization expense	1,752,000	2,140,000
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	4 years
Carrying Amount	1,090,000	1,090,000
Accumulated Amortization	426,000	221,000
Total future amortization expense	$ 664,000	$ 869,000