Schedule II - Valuation and Qualifying Accounts (Details) (Accounts receivable allowance [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounts receivable allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 740	$ 583	$ 1,185
Charged to Costs and Expenses, Additions	185	240	(160)
Charged to Other Accounts, Additions	0	0	0
Uncollectible Accounts Written-off	384	83	442
Balance at End of Period	$ 541	$ 740	$ 583