Guarantees and Commitments (Narrative) (Details)	3 Months Ended			12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2018 USD ($) Apartment	Dec. 31, 2019 USD ($)
Commitments, Contingencies and Guarantees [Line Items]
Number of apartments under the project | Apartment			37
Limited partner capital contribution commitment			$ 7,579,000
Annual LIHTCs mount awarded for the project			861,000
Total anticipated LIHTCs amount under the housing project			$ 8,613,000
Project investment amortization period		10 years	10 years	10 years
Total investment in limited partnership, net of amortization	$ 179,000	$ 190,000		$ 190,000
Other Assets [Member]
Commitments, Contingencies and Guarantees [Line Items]
Total investment in limited partnership, net of amortization	7,250,000	$ 7,249,000		7,249,000
Financial Standby Letters of Credit [Member]
Commitments, Contingencies and Guarantees [Line Items]
Commitments to extend credit	$ 19,758,000			$ 26,574,000