Goodwill and Other Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Other Intangible Assets
Gross Carrying Amount	$ 146,138	$ 145,156
Accumulated Amortization	(61,010)	(58,485)
Other intangible assets, net	85,128	86,671	86,671
Aggregate amortization expense	5,147	5,044
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2014	15,651
2015	19,094
2016	16,162
2017	9,924
2018	6,350
Thereafter	17,947
Other intangible assets, net	85,128	86,671	86,671
Noncontractual customer relationships [Member]
Other Intangible Assets
Gross Carrying Amount	109,330	109,842
Accumulated Amortization	(44,281)	(41,895)
Other intangible assets, net	65,049	67,947
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	65,049	67,947
Covenants not-to-compete [Member]
Other Intangible Assets
Gross Carrying Amount	8,718	8,843
Accumulated Amortization	(4,361)	(4,661)
Other intangible assets, net	4,357	4,182
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	4,357	4,182
Favorable lease asset [Member]
Other Intangible Assets
Gross Carrying Amount	9,537	7,458
Accumulated Amortization	(4,535)	(4,373)
Other intangible assets, net	5,002	3,085
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	5,002	3,085
Trademarks [Member]
Other Intangible Assets
Gross Carrying Amount	12,655	13,115
Accumulated Amortization	(4,308)	(4,194)
Other intangible assets, net	8,347	8,921
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	8,347	8,921
Contracts [Member]
Other Intangible Assets
Gross Carrying Amount	608	608
Accumulated Amortization	(326)	(305)
Other intangible assets, net	282	303
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	282	303
Technology [Member]
Other Intangible Assets
Gross Carrying Amount	5,240	5,240
Accumulated Amortization	(3,153)	(3,015)
Other intangible assets, net	2,087	2,225
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	2,087	2,225
Client lists [Member]
Other Intangible Assets
Gross Carrying Amount	50	50
Accumulated Amortization	(46)	(42)
Other intangible assets, net	4	8
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Other intangible assets, net	$ 4	$ 8