Other Identifiable Intangible Assets (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross	$ 355,897,000	$ 319,981,000
Accumulated Amortization	(180,089,000)	(148,947,000)
Net	175,808,000	171,034,000
Amortization expense for finite-lived intangible assets	34,800,000	26,800,000	25,100,000
Disposal Group, Including Discontinued Operation, Intangible Assets, Net	600,000
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	315,639,000	282,864,000
Accumulated Amortization	(162,278,000)	(135,032,000)
Net	153,361,000	147,832,000
Noncompete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	9,150,000	9,264,000
Accumulated Amortization	(6,659,000)	(5,438,000)
Net	2,491,000	3,826,000
Trade names and licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	31,108,000	27,853,000
Accumulated Amortization	(11,152,000)	(8,477,000)
Net	$ 19,956,000	$ 19,376,000