Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Future minimum lease payments under non-cancelable operating leases [Abstract]
Payments Due in Year One	$ 92,275,000
Payments Due in Year Two	63,288,000
Payments Due in Year Three	40,082,000
Payments Due in Year Four	26,330,000
Payments Due in Year Five	15,952,000
Thereafter	21,856,000
Total minimum lease payments	259,783,000
Rent Expense	$ 117,000,000	$ 118,000,000	$ 125,000,000