Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Unrealized gains on investment securities, before tax [Abstract]
Unrealized holding gains arising during period, before tax				$ 1,768	$ 5,107
Less adjustment for impaired investments, before tax					(146)
Less adjustment for impaired investments, tax					(50)
Less adjustment for impaired investments, net of tax (2)	[1]	$ 0	$ (96)	0	(96)
Less reclassification adjustment for gains realized in net income, before tax				276	1,102
Unrealized gains on investment securities, before tax				1,492	4,151
Unrecognized benefit obligation expense, before tax [Abstract]
Less reclassification adjustment for amortization, before tax				(27)	(154)
Unrecognized benefit obligation				27	(154)
Unrealized loss on derivative instrument, before tax				30	(674)
Other comprehensive income net, before tax				1,549	3,323
Unrealized gains on investment securities, tax [Abstract]
Unrealized holding gains arising during period, tax		274	659	602	1,888
Less reclassification adjustment for gains realized in net income, tax			250	94	375
Unrealized gains on investment securities, tax				508	1,563
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		(13)	63	(10)	229
Other comprehensive income net, tax				518	1,334
Unrealized gains on investment securities [Abstract]
Unrealized holding gains arising during period, net of tax	[2]	534	886	1,166	3,219
Less reclassification adjustment for gains realized in net income, net of tax	[3]	182	485	182	727
Unrealized gains (losses) on investment securities, net of tax		352	497	984	2,588
Unrecognized benefit obligation expense [Abstract]
Less reclassification adjustment for amortization, net of tax	[4]	14	(51)	27	(154)
Unrecognized benefit obligation expense		14	(51)	27	(154)
Unrealized loss on derivative instrument, net of tax	[5]	(25)	(123)	20	(445)
Other comprehensive income (loss)		341	$ 323	1,031	$ 1,989
Unrecognized benefit obligation		(4,111)		(4,111)		$ (4,138)
Unrealized gain (loss) on AFS investments		229		229		(755)
Unrealized loss on derivative instrument		(306)		(306)		(326)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total		$ (4,188)		$ (4,188)		$ (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 $50 thousand in taxes for the three and six months ended June 30, 2016. See Note 14. Comprehensive Income.

[2] Net of $274 thousand and $600 thousand in tax expense for the three and six months ended June 30, 2017, respectively, and $659 thousand and $1.9 million for the three and six months ended June 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 $94 thousand in income taxes for the three and six months ended June 30, 2017 and $250 thousand and $375 thousand in taxes for the three and six months ended June 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 benefit of $13 thousand for the three months ended June 30, 2017 and a tax expense of $10 thousand for the six months ended June 30, 2017 and $63 thousand and $229 thousand in tax benefit for the three and six months ended June 30, 2016, respectively.