11. INCOME TAXES - provision for income taxes (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income tax statutory rate	34.00%	34.00%	34.00%
State franchise tax, net of Federal tax effect	6.30%	4.60%	1.80%
Tax benefit of interest on obligations of states and political subdivisions	(4.00%)	(6.50%)	(7.20%)
Tax-exempt income from life insurance policies	(1.90%)	(2.90%)	(2.20%)
Equity compensation expense	0.10%	0.10%	0.20%
Other	0.00%	(0.10%)	(5.50%)
Effective tax rate	34.50%	29.20%	21.10%