SCHEDULE II - Valuation and Qualifying Accounts (Details) (Reserve deducted from assets: accumulated provision for uncollectible accounts., USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reserve deducted from assets: accumulated provision for uncollectible accounts.
Valuation and Qualifying Accounts
Balance At Beginning Of Period	$ 1,025,177	$ 1,387,673	$ 1,137,644
Charged To Income	3,463,797	2,213,988	3,052,397
Charged to Other Accounts	2,128,325	2,013,959	1,956,549
Deductions From Reserve	5,596,662	4,590,443	4,758,917
Balance At Close of Period	$ 1,020,637	$ 1,025,177	$ 1,387,673