Goodwill and Other Intangible Assets (Details 1) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Remainder of 2012	$ 16,198,000
2013	19,348,000
2014	17,022,000
2015	15,157,000
2016	11,933,000
Thereafter	32,627,000
Total	112,285,000
Other Intangible Assets
Gross Carrying Amount	150,908,000		129,075,000
Accumulated Amortization	(38,623,000)		(36,672,000)
Net Carrying Amount	112,285,000		92,403,000
Aggregate amortization expense	4,876,000	2,655,000
Goodwill and Other Intangible Assets (Textuals) [Abstract]
Accumulated impairment losses	21,300,000
Noncontractual customer relationships [Member]
Other Intangible Assets
Gross Carrying Amount	100,723,000		82,891,000
Accumulated Amortization	(24,444,000)		(21,147,000)
Net Carrying Amount	76,279,000		61,744,000
Covenants not-to-compete [Member]
Other Intangible Assets
Gross Carrying Amount	13,350,000		13,035,000
Accumulated Amortization	(7,191,000)		(8,067,000)
Net Carrying Amount	6,159,000		4,968,000
Favorable lease asset [Member]
Other Intangible Assets
Gross Carrying Amount	5,571,000		5,571,000
Accumulated Amortization	(1,823,000)		(3,210,000)
Net Carrying Amount	3,748,000		2,361,000
Trademarks [Member]
Other Intangible Assets
Gross Carrying Amount	8,162,000		7,405,000
Accumulated Amortization	(1,954,000)		(1,686,000)
Net Carrying Amount	6,208,000		5,719,000
Contracts [Member]
Other Intangible Assets
Gross Carrying Amount	4,061,000		3,500,000
Accumulated Amortization	(296,000)		(185,000)
Net Carrying Amount	3,765,000		3,315,000
Technology [Member]
Other Intangible Assets
Gross Carrying Amount	18,957,000		16,589,000
Accumulated Amortization	(2,872,000)		(2,342,000)
Net Carrying Amount	16,085,000		14,247,000
Client lists [Member]
Other Intangible Assets
Gross Carrying Amount	84,000		84,000
Accumulated Amortization	(43,000)		(35,000)
Net Carrying Amount	$ 41,000		$ 49,000