Fair Value Disclosures, Quantitative Information About Level 3 (Details) - Significant Un-observable Inputs (Level 3) [Member]	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member]
Asset Fair Value [Abstract]
Servicing asset fair value	$ 23,151,000	$ 15,699,000
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Present Value of Net Servicing Revenue [Member] | Float Rate [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	0.0307	0.0224
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Minimum [Member] | Cost to Service [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	68	66
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Minimum [Member] | Ancillary Income [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	20	20
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Minimum [Member] | Present Value of Net Servicing Revenue [Member] | Discount Rate [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	0.1	0.0988
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Maximum [Member] | Cost to Service [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	317	216
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Maximum [Member] | Ancillary Income [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	36	36
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Maximum [Member] | Present Value of Net Servicing Revenue [Member] | Discount Rate [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	0.13	0.1100
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Weighted Average [Member] | Cost to Service [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	81	81
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Weighted Average [Member] | Ancillary Income [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	22	23
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Weighted Average [Member] | Present Value of Net Servicing Revenue [Member] | Discount Rate [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	0.1015	0.1011
Recurring Basis [Member] | Capitalized Mortgage Loan Servicing Rights [Member] | Weighted Average [Member] | Present Value of Net Servicing Revenue [Member] | Float Rate [Member]
Ranges and Weighted Average [Abstract]
Servicing asset measurement input	0.0307	0.0224
Nonrecurring Basis [Member] | Impaired Loans Commercial [Member]
Asset Fair Value [Abstract]
Impaired loans fair value	$ 1,169,000	$ 1,334,000
Nonrecurring Basis [Member] | Impaired Loans Commercial [Member] | Minimum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	(0.325)	(0.325)
Nonrecurring Basis [Member] | Impaired Loans Commercial [Member] | Maximum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	0.250	0.250
Nonrecurring Basis [Member] | Impaired Loans Commercial [Member] | Weighted Average [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	(0.045)	(0.045)
Nonrecurring Basis [Member] | Impaired Loans Mortgage [Member]
Asset Fair Value [Abstract]
Impaired loans fair value	$ 598,000	$ 546,000
Nonrecurring Basis [Member] | Impaired Loans Mortgage [Member] | Minimum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	(0.401)	(0.211)
Nonrecurring Basis [Member] | Impaired Loans Mortgage [Member] | Maximum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	0.304	(0.341)
Nonrecurring Basis [Member] | Impaired Loans Mortgage [Member] | Weighted Average [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Impaired loans measurement input	(0.019)	(0.027)
Nonrecurring Basis [Member] | Other Real Estate Mortgage [Member]
Asset Fair Value [Abstract]
Other real estate fair value	$ 95,000	$ 251,000
Nonrecurring Basis [Member] | Other Real Estate Mortgage [Member] | Minimum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Other real estate measurement input	0.022	(0.33)
Nonrecurring Basis [Member] | Other Real Estate Mortgage [Member] | Maximum [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Other real estate measurement input	0.341	0.445
Nonrecurring Basis [Member] | Other Real Estate Mortgage [Member] | Weighted Average [Member] | Sales Comparison Approach [Member] | Adjustment for Differences Between Comparable Sales [Member]
Ranges and Weighted Average [Abstract]
Other real estate measurement input	0.179	(0.010)