Other Intangible Assets Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount					$ 8,690	$ 8,597
Accumulated Amortization					(6,401)	(5,901)
Net Carrying Amount		$ 2,696	$ 3,107	$ 3,625	2,289	2,696
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Beginning Balance		2,696	3,107	3,625
Intangible Assets Acquired		93	146	107
Impairment of Intangible Assets, Finite-lived		0	0	(38)
Amortization of Intangible Assets		(500)	(557)	(587)
Finite-Lived Intangible Assets, Ending Balance		2,289	2,696	3,107
Depositor Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]				2,247	2,247
Accumulated Amortization	[1]				(2,247)	(2,247)
Net Carrying Amount	[1]	0	0	10	0	0
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Beginning Balance	[1]	0	0	10
Intangible Assets Acquired	[1]	0	0	0
Impairment of Intangible Assets, Finite-lived	[1]	0	0	0
Amortization of Intangible Assets	[1]	0	0	(10)
Finite-Lived Intangible Assets, Ending Balance	[1]	0	0	0
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[2]				2,061	1,968
Accumulated Amortization	[2]				(1,624)	(1,403)
Net Carrying Amount	[2]	565	679	832	437	565
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Beginning Balance	[2]	565	679	832
Intangible Assets Acquired	[2]	93	146	107
Impairment of Intangible Assets, Finite-lived	[2]	0	0	0
Amortization of Intangible Assets	[2]	(221)	(260)	(260)
Finite-Lived Intangible Assets, Ending Balance	[2]	437	565	679
Customer Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]				4,382	4,382
Accumulated Amortization	[1]				(2,530)	(2,251)
Net Carrying Amount	[1]	2,131	2,428	2,783	$ 1,852	$ 2,131
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Beginning Balance	[1]	2,131	2,428	2,783
Intangible Assets Acquired	[1]	0	0	0
Impairment of Intangible Assets, Finite-lived	[1]	0	0	(38)
Amortization of Intangible Assets	[1]	(279)	(297)	(317)
Finite-Lived Intangible Assets, Ending Balance	[1]	$ 1,852	$ 2,131	$ 2,428

[1] Amortization of depositor intangibles and customer intangibles are reported in the Consolidated Statements of Income as a component of other operating expense.

[2] Amortization of mortgage servicing rights is reported in the Consolidated Statements of Income as a reduction of mortgage servicing fee income, which is included with fees for other services to customers.