SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for doubtful accounts
VALUATION AND QUALIFYING ACCOUNTS
Balance at the Beginning of the Period	$ 8,257	$ 8,560	$ 9,923
Charged to Costs and Expenses	(595)	1,642	(252)
Deductions from Reserve	(911)	(1,945)	(1,111)
Balance at the End of the Period	6,751	8,257	8,560
Deferred tax valuation allowance
VALUATION AND QUALIFYING ACCOUNTS
Balance at the Beginning of the Period	6,326	5,619	5,480
Charged to Costs and Expenses	1,362	1,020	1,344
Deductions from Reserve	(655)	(313)	(1,205)
Balance at the End of the Period	$ 7,033	$ 6,326	$ 5,619