Valuation Allowances and Reserves (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation Allowances and Reserves [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 1,656	$ 2,518	$ 2,895	$ 2,950
Valuation Allowances and Reserves, Charged to Cost and Expense	199	1,130	1,919
Valuation Allowances and Reserves, Deductions	1,061	1,507	1,974
Valuation Allowances and Reserves, Charged to Other Accounts	$ 0	$ 0	$ 0