Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Unrealized gains on investment securities, before tax [Abstract]
Unrealized holding gains arising during period, before tax				$ 2,011	$ 6,570
Less reclassification adjustment for gains realized in net income, before tax				652	330
Unrealized gains on investment securities, before tax				1,359	6,240
Unrecognized benefit obligation expense, before tax [Abstract]
Less reclassification adjustment for amortization, before tax				(51)	(85)
Unrecognized benefit obligation				(51)	85
Unrealized loss on derivative instrument, before tax				(708)
Other comprehensive income net, before tax				600	6,325
Unrealized gains on investment securities, tax [Abstract]
Unrealized holding gains arising during period, tax				691	2,101
Less reclassification adjustment for gains realized in net income, tax				222	112
Unrealized gains on investment securities, tax				469	1,989
Unrecognized benefit obligation expense, tax [Abstract]
Less reclassification adjustment for amortization, tax					(29)
Unrecognized benefit obligation, tax					(29)
Unrealized loss on derivative instrument, tax				(241)
Other comprehensive income net, tax				228	2,018
Unrealized gains on investment securities [Abstract]
Unrealized holding gains arising during period, net of tax		$ 1,190	$ (80)	1,320	4,469
Less reclassification adjustment for gains realized in net income, net of tax	[1]	52	157	430	218
Unrealized gains (losses) on investment securities, net of tax		1,138	(237)	890	4,251
Unrecognized benefit obligation expense [Abstract]
Less reclassification adjustment for amortization, net of tax	[2]	(17)	(18)	(51)	(56)
Unrecognized benefit obligation expense		(17)	(18)	(51)	(56)
Unrealized loss on derivative instrument, net of tax		(282)		(467)		$ (187)
Other comprehensive income (loss)		839	$ (219)	372	$ 4,307
Unrecognized benefit obligation		(4,076)		(4,076)		(4,025)
Unrealized gains (losses) on AFS investments		2,423		2,423		1,720
Accumulated other comprehensive loss		$ (2,120)		$ (2,120)		$ (2,492)

[1] Gross amounts are included in net gains on the sale of AFS investment securities on the Consolidated Statements of Income. See Note 15. C

[2] Gross amounts are included in salaries and benefits on the Consolidated Statements of Income. See Note 15. Comprehensive Income (Loss).