Consolidated Statements Of Cash Flows (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Non cash net unrealized (gain) loss on investments, net of deferred tax (provision) benefit	$ (2,144,901)	$ (133,892)	$ 708,564
Adjustments to postretirement benefits obligation, net of deferred tax (provision) benefit	$ (23,676)	$ 192	$ 21,612