Investment Securities - Contractual maturity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Amortized Cost
After One Year through Five Years	$ 123,000
After Five Years through Ten Years	1,716,000
After Ten Years	3,503,000
Amortized Cost	5,342,000
Fair Value
After One Year through Five Years	123,000
After Five Years through Ten Years	1,708,000
After Ten Years	3,489,000
Fair value	5,320,000
Securities pledged to secure advances from the FHLB	0	$ 0
Proceeds from sales and calls of available-for-sale investment securities	683,000	1,076,000
Realized gains (losses)	$ 6,000	$ (55,000)