Basis of Presentation and Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011	Dec. 31, 2010
Intangible assets and deferred debt issuance costs
Deferred financing costs, Gross Carrying Amount	$ 7,837,000	$ 6,828,000
Deferred financing costs, Accumulated Amortization	(3,033,000)	(1,527,000)
Intangible assets and deferred financing costs, Gross Carrying Amount	34,130,000	28,116,000
Intangible assets and deferred financing costs, Accumulated Amortization	(10,134,000)	(5,845,000)
Amortization of deferred financing costs	1,508,000	1,327,000	1,180,000
Amortization expense for finite life intangible assets	2,800,000	2,000,000	1,400,000
Estimated future intangible amortization expense
2013	2,631,000
2014	2,377,000
2015	2,146,000
2016	1,936,000
2017	1,745,000
Thereafter	8,357,000
Total	19,192,000
Segment Reporting
Number of segments in which the entity operates	1
Customer- related
Intangible assets and deferred debt issuance costs
Intangible assets, Gross Carrying Amount	25,083,000	20,078,000
Intangible assets, Accumulated Amortization	(5,926,000)	(3,193,000)
Customer- related | Minimum
Intangible assets and deferred debt issuance costs
Intangible assets estimated useful lives	13 years
Customer- related | Maximum
Intangible assets and deferred debt issuance costs
Intangible assets estimated useful lives	18 years
Contract based
Intangible assets and deferred debt issuance costs
Intangible assets, Gross Carrying Amount	1,210,000	1,210,000
Intangible assets, Accumulated Amortization	$ (1,175,000)	$ (1,125,000)
Contract based | Minimum
Intangible assets and deferred debt issuance costs
Intangible assets estimated useful lives	7 years
Contract based | Maximum
Intangible assets and deferred debt issuance costs
Intangible assets estimated useful lives	9 years