Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Other Intangible Assets [Abstract]
Customer lists	$ 70,080,000		$ 69,763,000
Covenants not to compete	26,274,000		29,441,000
Trademarks	10,067,000		9,551,000
Patents	2,840,000		2,840,000
Finite-lived intangible assets, gross	109,261,000		111,595,000
Accumulated amortization	(69,304,000)		(69,397,000)
Finite-lived intangible assets, net	39,957,000		42,198,000
Licenses	17,854,000		17,796,000
Other intangible assets, net	57,811,000		59,994,000
Amortization expense	$ 2,900,000	$ 3,600,000