Leases Operating Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$ 111,861,000	$ 94,137,000	$ 77,960,000
Operating Leases, Future Minimum Payments Due [Abstract]
Operating Leases, Future Minimum Payments Due, Current	88,502,000
Operating Leases, Future Minimum Payments, Due in Two Years	82,568,000
Operating Leases, Future Minimum Payments, Due in Three Years	69,702,000
Operating Leases, Future Minimum Payments, Due in Four Years	57,418,000
Operating Leases, Future Minimum Payments, Due in Five Years	37,769,000
Operating Leases, Future Minimum Payments, Due Thereafter	149,771,000
Operating Leases, Future Minimum Payments Due	$ 485,730,000