Leases (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Operating Leased Assets [Line Items]
2013	$ 41,932
2014	31,432
2015	25,763
2016	20,506
2017	15,153
Thereafter	89,419
Total Due	224,205
Rent expense	74,849		73,801	69,448
Real Estate [Member]
Operating Leased Assets [Line Items]
2013	31,358
2014	26,686
2015	22,655
2016	19,150
2017	14,674
Thereafter	88,553
Total Due	203,076
Vehicles and Equipment [Member]
Operating Leased Assets [Line Items]
2013	10,574	[1]
2014	4,746	[1]
2015	3,108	[1]
2016	1,356	[1]
2017	479	[1]
Thereafter	866	[1]
Total Due	$ 21,129	[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] eases vehicles with contractual terms of 36 to 60 months that are cancellable after 12 months without penalty. Future minimum lease payments reflect only the minimum payments during the initial 12-month non-cancellable term.