Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012 Y	Dec. 31, 2011 Y
Finite-lived intangible assets, net [Abstract]
Gross intangibles	$ 60,875	$ 60,437
Accumulated amortization	(17,932)	(15,965)
Net intangibles	42,943	44,472
Weighted average amortization period (years)	8	8
Customer Relationships [Member]
Finite-lived intangible assets, net [Abstract]
Gross intangibles	58,465	58,027
Accumulated amortization	(15,990)	(14,056)
Net intangibles	42,475	43,971
Weighted average amortization period (years)	8	8
Trade Name [Member]
Finite-lived intangible assets, net [Abstract]
Gross intangibles	1,000	1,000
Accumulated amortization	(639)	(639)
Net intangibles	361	361
Weighted average amortization period (years)	3	3
Non-compete Agreements [Member]
Finite-lived intangible assets, net [Abstract]
Gross intangibles	560	560
Accumulated amortization	(560)	(560)
Weighted average amortization period (years)	1	1
Proprietary Software [Member]
Finite-lived intangible assets, net [Abstract]
Gross intangibles	850	850
Accumulated amortization	(743)	(710)
Net intangibles	$ 107	$ 140
Weighted average amortization period (years)	2	2