ACCUMULATED OTHER COMPREHENSIVE INCOME - Components of Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2012	$ 47,752,375	[1]
Other comprehensive income (loss) before reclassifications	15,684,647	[1]
Amounts reclassified from accumulated other comprehensive income	(4,426,533)	[1]
Other comprehensive income	11,258,114	[1]	20,411,865		2,845,023
Balance at December 31, 2013	59,010,489	[1]	47,752,375	[1]
Unrealized Gains and (Losses) on Available-for-sale securities
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2012	69,805,305	[1]
Other comprehensive income (loss) before reclassifications	(15,581,644)	[1]
Amounts reclassified from accumulated other comprehensive income	(5,847,754)	[1]
Other comprehensive income	(21,429,398)	[1]
Balance at December 31, 2013	48,375,907	[1]
Unrecognized pension and postretirement benefit obligations
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2012	(22,052,930)	[1]
Other comprehensive income (loss) before reclassifications	31,266,291	[1]
Amounts reclassified from accumulated other comprehensive income	1,421,221	[1]
Other comprehensive income	32,687,512	[1]
Balance at December 31, 2013	$ 10,634,582	[1]

[1] All amounts are net of tax. Amounts in parentheses indicate debits.