Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Unrealized gains on investment securities, before tax [Abstract]
Unrealized holding gains arising during period, before tax				$ 1,583	$ 3,776
Less adjustment for impaired investments, before tax					(181)
Less adjustment for impaired investments, tax			$ (12)		(62)
Less adjustment for impaired investments, net of tax (2)	[1]	$ 0	(23)	0	(119)
Less reclassification adjustment for gains realized in net income, before tax				308	1,382
Unrealized gains on investment securities, before tax				1,275	2,575
Unrecognized benefit obligation expense, before tax [Abstract]
Less reclassification adjustment for amortization, before tax				(39)	(232)
Unrecognized benefit obligation				39	(232)
Unrealized loss on derivative instrument, before tax				86	(475)
Other comprehensive income net, before tax				1,400	1,868
Unrealized gains on investment securities, tax [Abstract]
Unrealized holding gains arising during period, tax		65	454	537	1,434
Less reclassification adjustment for gains realized in net income, tax		11	95	105	470
Unrealized gains on investment securities, tax				432	1,026
Unrecognized benefit obligation expense, tax [Abstract]
Less reclassification adjustment for amortization, tax				0	0
Unrecognized benefit obligation, tax				0	0
Unrealized loss on derivative instrument, tax		(19)	68	(29)	161
Other comprehensive income net, tax				461	865
Unrealized gains on investment securities [Abstract]
Unrealized holding gains arising during period, net of tax	[2]	(120)	(877)	1,046	2,342
Less reclassification adjustment for gains realized in net income, net of tax	[3]	21	185	203	912
Unrealized gains (losses) on investment securities, net of tax		(141)	(1,039)	843	1,549
Unrecognized benefit obligation expense [Abstract]
Less reclassification adjustment for amortization, net of tax	[4]	12	(78)	39	(232)
Unrecognized benefit obligation expense		12	(78)	39	(232)
Unrealized loss on derivative instrument, net of tax	[5]	37	131	57	(314)
Other comprehensive income (loss)		(92)	$ (986)	939	$ 1,003
Unrecognized benefit obligation		(4,099)		(4,099)		$ (4,138)
Unrealized gain (loss) on AFS investments		88		88		(755)
Unrealized loss on derivative instrument		(269)		(269)		(326)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total		$ (4,280)		$ (4,280)		$ (5,219)

[1] Gross amounts are included in total other-than-temporary impairment on AFS investment securities on the Consolidated Statements of Income in total non-interest income, net of $12 thousand and $62 thousand in taxes for the three and nine months ended September 30, 2016. See Note 14. Comprehensive Income.

[2] Net of a tax benefit of $65 thousand and $537 thousand in tax expense for the three and nine months ended September 30, 2017, respectively, and a tax benefit of $454 thousand and $1.4 million in tax expense for the three and nine months ended September 30, 2016, respectively.

[3] Gross amounts are included in net gains on the sale of AFS investment securities on the Consolidated Statements of Income in total non-interest income; amounts in the above table are net of $11 thousand and $105 thousand in income taxes for the three and nine months ended September 30, 2017, respectively and $95 thousand and $470 thousand in taxes for the three and nine months ended September 30, 2016, respectively. See Note 14. Comprehensive Income.

[4] Gross amounts are included in salaries and benefits on the Consolidated Statements of Income in non-interest expense.

[5] Net of a tax expense of $19 thousand and $29 thousand for the three and nine months ended September 30, 2017, respectively and a tax expense of $68 thousand and $161 thousand in tax benefit for the three and nine months ended September 30, 2016, respectively.