INCOME TAX - Deferred tax asset (liability) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Allowance for loan losses		$ 5,514	$ 8,590
State net operating loss carryforward		3,563	3,876
Credit carryforwards		3,538	6,439
OREO write-downs		519	583
Other		2,198	3,456
Total assets		15,332	22,944
Liabilities
Depreciation		(3,196)	(6,041)
Mortgage servicing rights		(1,786)	(2,717)
Unrealized gain on securities AFS		(1,358)	(1,658)
Intangibles		(1,478)	(434)
Deferred loan fees/costs		(1,479)	(2,058)
Other		(2,419)	(3,725)
Total liabilities		(11,716)	(16,633)
Less: Valuation allowance		(3,087)	(2,934)
Net deferred tax asset		529
Net deferred tax liability			3,377
Indiana state operating loss carryforwards		92,046
Valuation allowance for deferred tax assets, excluding Indiana state loss carryforward and all Indiana deferred tax activity since 2004		0
Retained earnings for which no deferred income tax liability has been recognized		16,112
Deferred income tax liability recognized on retained earnings related to previously acquired institutions		0
Unrecorded deferred income tax liability		3,384	5,639
Unrecognized Tax Benefits
Interest and penalties recorded in the income statement		0	0
Amount accrued for interest and penalties		$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Deferred Tax Assets, Regulatory Assets and Liabilities		$ 2,505
Forecast 2019
Unrecognized Tax Benefits
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Alternative minimum tax credit carryforwards
Liabilities
Tax credit carryforwards		3,363
General business credit carryforwards
Liabilities
Tax credit carryforwards		$ 175