SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) (Allowance for doubtful accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 1,614	$ 1,691	$ 1,843
Charged to Expense	211	240	240
Accounts Written Off	(111)	(317)	(392)
Balance at End of Period	$ 1,714	$ 1,614	$ 1,691