Fair Value - Assets and Liabilities Measured on a Non-Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Impaired loans
Total impaired loans	$ 24	$ 1,775
Mortgage servicing rights	288	629
Real estate held for sale
Total real estate held for sale		705
Commercial Real Estate [Member]
Impaired loans
Total impaired loans	24	1,456
Real estate held for sale
Total real estate held for sale		705
Commercial [Member]
Impaired loans
Total impaired loans		319
Fair Value, Inputs, Level 1 [Member]
Impaired loans
Total impaired loans	0	0
Mortgage servicing rights	0	0
Real estate held for sale
Total real estate held for sale		0
Fair Value, Inputs, Level 1 [Member] | Commercial Real Estate [Member]
Impaired loans
Total impaired loans	0	0
Real estate held for sale
Total real estate held for sale		0
Fair Value, Inputs, Level 1 [Member] | Commercial [Member]
Impaired loans
Total impaired loans		0
Fair Value, Inputs, Level 2 [Member]
Impaired loans
Total impaired loans	0	0
Mortgage servicing rights	288	629
Real estate held for sale
Total real estate held for sale		0
Fair Value, Inputs, Level 2 [Member] | Commercial Real Estate [Member]
Impaired loans
Total impaired loans	0	0
Real estate held for sale
Total real estate held for sale		0
Fair Value, Inputs, Level 2 [Member] | Commercial [Member]
Impaired loans
Total impaired loans		0
Fair Value, Inputs, Level 3 [Member]
Impaired loans
Total impaired loans	24	1,775
Mortgage servicing rights	0	0
Real estate held for sale
Total real estate held for sale		705
Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate [Member]
Impaired loans
Total impaired loans	$ 24	1,456
Real estate held for sale
Total real estate held for sale		705
Fair Value, Inputs, Level 3 [Member] | Commercial [Member]
Impaired loans
Total impaired loans		$ 319