Guarantees, Commitments and Contingencies (Narrative) (Details)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2018 USD ($) Apartment	Jun. 30, 2019 USD ($)	Jun. 30, 2018 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		$ 211,000		$ 233,000
Minimum net assets qualified for small banks assessment credits		10,000,000,000
Total assessment credit		$ 492,000
Minimum [Member]
Commitments, Contingencies and Guarantees [Line Items]
Small bank growth reserve ratio		1.15%
Reserve ratio for assessment credits to be contingent		1.38%
Maximum [Member]
Commitments, Contingencies and Guarantees [Line Items]
Small bank growth reserve ratio		1.35%
Other Assets [Member]
Commitments, Contingencies and Guarantees [Line Items]
Total investment in limited partnership		$ 4,356,000		1,710,000
Financial Standby Letters of Credit [Member]
Commitments, Contingencies and Guarantees [Line Items]
Commitments to extend credit		$ 29,797,000		$ 20,839,000