Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingency [Abstract]
Supplemental Unemployment Benefits, Severance Benefits	$ 7,800,000
Operating Leases, Rent Expense	24,100,000	23,200,000	21,600,000
Operating Leases, Future Minimum Payments Due [Abstract]
Operating Leases, Future Minimum Payments Due, Current	21,804,000
Operating Leases, Future Minimum Payments, Due in Two Years	17,319,000
Operating Leases, Future Minimum Payments, Due in Three Years	14,915,000
Operating Leases, Future Minimum Payments, Due in Four Years	11,578,000
Operating Leases, Future Minimum Payments, Due in Five Years	8,751,000
Operating Leases, Future Minimum Payments, Due Thereafter	29,679,000
Operating Leases, Future Minimum Payments Due	$ 104,046,000