SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (Allowance for Doubtful Accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 1,691	$ 1,843	$ 2,090
Charged to Expense	240	240	220
Accounts Written Off	(317)	(392)	(467)
Balance at End of Period	$ 1,614	$ 1,691	$ 1,843