Property & Equipment Depreciation Expense (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Property And Equipment [Abstract]
Depreciation Expense	$ 5,900,000	$ 6,000,000	$ 12,000,000	$ 11,500,000
Depreciation Expense Recorded in Cost of Sales	800,000	1,100,000	1,600,000	2,600,000
Asset Impairment Charges	$ 202,000	$ 106,000	$ 202,000	$ 819,000