Leasing Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Leases [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 28,367,000
Operating Leases, Future Minimum Payments, Due in Two Years	27,536,000
Operating Leases, Future Minimum Payments, Due in Three Years	19,951,000
Operating Leases, Future Minimum Payments, Due in Four Years	15,533,000
Operating Leases, Future Minimum Payments, Due in Five Years	12,262,000
Operating Leases, Future Minimum Payments, Due Thereafter	15,395,000
Operating Leases, Future Minimum Payments Due	119,044,000
Operating Leases, Rent Expense, Net	$ 58,400,000	$ 56,600,000	$ 56,700,000