Valuation and Qualifying Accounts - Schedule (Details) (Allowance for Doubtful Accounts Receivable Year Ended December 31:, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable Year Ended December 31:
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Period	$ 2,491	$ 1,885	$ 2,789
Additions Charged to Revenues, Costs, Expenses	1,043	1,717	1,749
Deductions Amounts Charged Off-Net	1,507	1,111	2,653
Increase (Decrease) Recorded Acquisitions (Divestitures)	0	0	0
Balance End of Period	$ 2,027	$ 2,491	$ 1,885