Income Taxes (Components Of Deferred Income Tax Amounts) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Provision for bad debts	$ 7,123	$ 7,299
Employee retirement and other benefit obligations	54,708	49,028
Workers' compensation	8,526	8,284
Deferred compensation	15,502	18,909
Credits and net operating loss carryforwards	42,289	47,847
Other	16,427	18,727
Total deferred income tax assets	144,575	150,094
Amortization of intangible assets	(20,475)	(18,819)
Property and equipment basis differences	(8,823)	(3,203)
Other	(4,742)	(6,381)
Total deferred income tax liabilities	(34,040)	(28,403)
Valuation allowance	(36,334)	(30,983)
Total deferred income tax assets, net	$ 74,201	$ 90,708