Goodwill and Intangible Assets Schedule of Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 73,346	$ 66,603
Accumulated amortization on intangible assets	(35,145)	(25,626)
Intangible assets (net of accumulated amortization of $35,144 and $25,626 at December 31, 2012 and 2011, respectively)	38,201	40,977
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8,711	8,643
Accumulated amortization on intangible assets	(6,480)	(5,177)
Finite-Lived Intangible Assets, Net	2,231	3,466
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	55,933	49,308
Accumulated amortization on intangible assets	(23,120)	(15,151)
Finite-Lived Intangible Assets, Net	32,813	34,157
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2,707	2,657
Accumulated amortization on intangible assets	(2,670)	(2,657)
Finite-Lived Intangible Assets, Net	37	0
Software [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2,875	2,875
Accumulated amortization on intangible assets	(2,875)	(2,641)
Finite-Lived Intangible Assets, Net	0	234
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	3,120	3,120
Accumulated amortization on intangible assets	0	0
Finite-Lived Intangible Assets, Net	$ 3,120	$ 3,120