Leases (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Operating Leased Assets [Line Items]
2012	$ 43,192
2013	31,388
2014	24,942
2015	18,630
2016	14,404
Thereafter	11,238
Total Due	143,794
Rent expense	73,801		69,448	74,914
Real Estate [Member]
Operating Leased Assets [Line Items]
2012	29,766
2013	25,912
2014	22,237
2015	17,359
2016	13,953
Thereafter	10,998
Total Due	120,225
Equipment [Member]
Operating Leased Assets [Line Items]
2012	13,426	[1]
2013	5,476	[1]
2014	2,705	[1]
2015	1,271	[1]
2016	451	[1]
Thereafter	240	[1]
Total Due	$ 23,569	[1]
Minimum [Member] | Automobiles [Member]
Operating Leased Assets [Line Items]
Term Of Operating Lease Cancellable In Twelve Month Period	36
Maximum [Member] | Automobiles [Member]
Operating Leased Assets [Line Items]
Term Of Operating Lease Cancellable In Twelve Month Period	60

[1] Leased vehicles with contractual terms of 36 to 60 months are cancellable after 12 months without penalty. Future minimum lease payments reflect only the minimum payments during the initial 12-month non-cancellable term.