Property and Equipment, Net - Depreciation Expense Table (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Depreciation Expense [Line Items]
Depreciation expense	$ 25,050	$ 25,940	$ 23,640
Continuing Operations [Member]
Depreciation Expense [Line Items]
Depreciation expense	25,050	23,770	21,600
Cost of Sales [Member] | Continuing Operations [Member]
Depreciation Expense [Line Items]
Depreciation expense	21,530	20,800	19,020
Selling, General and Administrative Expenses [Member] | Continuing Operations [Member]
Depreciation Expense [Line Items]
Depreciation expense	$ 3,520	$ 2,970	$ 2,580