Schedule II-Valuation and Qualifying Accounts (Details) (Allowance for Doubtful Accounts [Member], USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 303,910		$ 301,945		$ 315,333
Charged to cost and expenses	390,217		579,419		627,713
Deductions	274,127	[1]	577,454	[1]	641,101	[1]
Balance at end of period	$ 420,000		$ 303,910		$ 301,945

[1] Charges to the account are for the purpose for which the reserves were created.