Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Leases [Abstract]
Rental expense	$ 100,000,000	$ 117,000,000	$ 118,000,000
2013	90,936,000
2014	69,945,000
2015	49,835,000
2016	32,355,000
2017	18,647,000
Thereafter	22,360,000
Total minimum lease payments	$ 284,078,000