Debt Securities Held-to-Maturity - Held-to-Maturity Securities in a Continuous Unrealized Loss Positions (Details)	3 Months Ended
	Mar. 31, 2020 USD ($) loan	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities sold	$ 0	$ 0
Held-to-maturity securities pledged to secure borrowings and deposits	7,300,000
Unrealized losses
Less than 12 months			$ 0
12 months or more			5,000
Total			5,000
Estimated fair value
Less than 12 months			0
12 months or more			378,000
Total			378,000
Other-than-temporary impairment charge recognized in earnings	$ 0	$ 0
Mortgage Backed Securities Pass Through Certificates
Unrealized losses
Less than 12 months			0
12 months or more			5,000
Total			5,000
Estimated fair value
Less than 12 months			0
12 months or more			378,000
Total			$ 378,000
Number of mortgage-backed securities in unrealized loss position, greater than 12 months (loan) | loan	0