SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (Receivable Reserves, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Receivable Reserves
Movement in Valuation Allowances and Reserves
Balance at beginning of period	$ 11,113	$ 14,946	$ 18,785
Charged to cost and expenses	1,407	(347)	498
Additions (Deductions)	(2,148)	(3,486)	(4,337)
Balance at end of period	$ 10,372	$ 11,113	$ 14,946