ACCUMULATED OTHER COMPREHENSIVE INCOME - Components of Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at December 31, 2012				$ 47,752,375	[1]
Other comprehensive income (loss) before reclassifications				(17,438,821)	[1]
Amounts reclassified from accumulated other comprehensive income				(1,436,797)	[1]
Other comprehensive income (loss)	(630,830)		11,991,936	(18,875,618)	[1]	22,547,539
Balance at September 30, 2013	28,876,757	[1]		28,876,757	[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				(17,438,821)	[1]
Amounts reclassified from accumulated other comprehensive income				(2,502,717)	[1]
Other comprehensive income (loss)				(19,941,538)	[1]
Balance at September 30, 2013	49,863,767	[1]		49,863,767	[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				0	[1]
Amounts reclassified from accumulated other comprehensive income				1,065,920	[1]
Other comprehensive income (loss)				1,065,920	[1]
Balance at September 30, 2013	$ (20,987,010)	[1]		$ (20,987,010)	[1]

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