6. LONG-TERM DEBT (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	$ 75,000,000		$ 70,000,000
Line of Credit Facility, Interest Rate During Period	0.25%
Line of Credit Facility, Interest Rate at Period End	1.25%
Libor_Loan	$ 17,000,000	$ 35,000,000
Line of Credit Facility, Amount Outstanding	23,700,000
Line of Credit Facility, Current Borrowing Capacity	66,300,000
Dividends, Common Stock	$ 3,252,254	$ 3,017,979	$ 2,254,935