Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	$ 662,000	$ 525,000	$ 910,000
Charged to Revenues and Expenses	1,576,000	2,359,000	2,030,000
Deductions	(2,085,000)	(2,222,000)	(2,415,000)
Balance, end of period	153,000	662,000	525,000
Reduction to revenues	$ 1,600,000	$ 2,200,000	$ 190,000