INCOME TAXES, PROVISION FOR FEDERAL INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Provision for federal income taxes [Abstract]
Income taxes currently payable									$ 3,018	$ 3,515	$ 4,280
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability									(224)	0	0
Deferred income tax provision (benefit)									1,478	928	(58)
Provision for income taxes	$ 1,017	$ 1,040	$ 1,027	$ 1,188	$ 1,337	$ 995	$ 1,043	$ 1,068	$ 4,272	$ 4,443	$ 4,222