Fair Market Value of Financial Assets and Liabilities, Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 3,433	$ 3,236
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	7.00%	6.10%
Probability of default	0.00%	0.00%
Discount rate	10.00%	10.00%
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	27.00%	22.40%
Probability of default	100.00%	100.00%
Discount rate	11.50%	11.50%
Mortgage Servicing Rights [Member] | Discount Cash Flows, Computer Pricing Model [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Constant prepayment rate	9.50%	10.00%
Probability of default	3.00%	2.60%
Discount rate	10.10%	10.10%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 5,506	$ 3,192
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Marketability discount	0.00%	0.00%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Marketability discount	100.00%	76.70%
Impaired Loans (Collateral Dependent) [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Marketability discount	33.70%	26.80%
Other Real Estate Owned [Member] | Market Comparable Properties [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 4,388	$ 6,798
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member]
Unobservable inputs [Abstract]
Comparability adjustments	10.00%	5.00%
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member]
Unobservable inputs [Abstract]
Comparability adjustments	100.00%	51.80%
Other Real Estate Owned [Member] | Market Comparable Properties [Member] | Significant Unobservable Inputs (Level 3) [Member] | Weighted Average [Member]
Unobservable inputs [Abstract]
Comparability adjustments	14.90%	11.70%