COMMON STOCK AND EARNINGS PER SHARE - Summary of Common Stock and Earnings Per Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Available to Common Shareholders:
Net Income	$ 10,912,299	$ 12,746,392
Weighted Average Shares Outstanding	5,530,864	5,602,137
Common Shares Applicable to Stock
Options Using the Treasury Stock Method	31,036	21,277
Total Shares Applicable to Diluted Earnings Per Share	5,561,900	5,623,414
Per Share Information:
Basic Net Income per Share (in dollars per share)	$ 1.97	$ 2.28
Diluted Net Income per Share (in dollars per share)	$ 1.96	$ 2.27