Income Taxes - Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018
Deferred tax assets:
Allowance for loan losses	$ 2,694	$ 2,091	$ 1,822
Deferred loan costs/fees	209	83	47
Director/officer compensation plans	83	143	126
Net unrealized loss on securities available for sale	179	698	1,027
Economic performance accruals	504	273	273
Other real estate	31	53	58
Deferred revenue	87	110	111
Loan Discounts	2,391	1,750	846
FHLB Advances	107	104	0
Lease Liability	768	0	0
Other	58	17	10
Deferred tax assets	7,111	5,322	4,320
Deferred tax liabilities:
Office properties and equipment	(1,574)	(971)	(742)
Federal Home Loan Bank stock	(129)	(94)	(88)
Core Deposit Intangible	(1,937)	(1,771)	(987)
Bank Owned Life Insurance	0	(282)	0
Net gain on equity securities	(456)	0	0
Prepaid expenses	(137)	(159)	(155)
Mortgage servicing rights	(1,177)	(1,234)	(496)
Leases; right of use asset	(753)	0	0
Other acquired intangibles	(111)	(96)	(152)
Deferred tax liabilities	(6,274)	(4,607)	(2,620)
Net deferred tax assets	$ 837	$ 715	$ 1,700