Guarantees and Commitments (Narrative) (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($) Apartment	Sep. 30, 2019 USD ($) Apartment	Dec. 31, 2018 USD ($)
Commitments, Contingencies and Guarantees [Line Items]
Number of apartments under the project | Apartment	37	37
Limited partner capital contribution commitment	$ 7,579,000	$ 7,579,000
Project investment amortization period	10 years	10 years
Annual LIHTCs mount awarded for the project	$ 861,000	$ 861,000
Total anticipated LIHTCs amount under the housing project	$ 8,613,000	8,613,000
Total investment in limited partnership		201,000	$ 233,000
Other Assets [Member]
Commitments, Contingencies and Guarantees [Line Items]
Total investment in limited partnership		5,810,000	1,710,000
Financial Standby Letters of Credit [Member]
Commitments, Contingencies and Guarantees [Line Items]
Commitments to extend credit		$ 27,757,000	$ 20,839,000