Comprehensive Income Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015
Schedule of Comprehensive Income [Line Items]
Other comprehensive income, before reclassifications, net of tax	[1]	$ (810)		$ 543		$ 2,309		$ 384
Reclassification from Accumulated Other Comprehensive Income, net of tax	[1]	110		108		221		262
Other Comprehensive Income, before Tax		(1,086)		1,071		4,220		1,063
Other Comprehensive Income, Tax		386		(420)		(1,690)		(417)
Other Comprehensive Income	[1],[2]	(700)		651		2,530		646
Unrealized Gains and Losses on Available for Sale Securities [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income Loss Before Reclassifications Before Tax		(1,264)		892		3,868		631
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit		454		(349)		(1,559)		(247)
Other comprehensive income, before reclassifications, net of tax		(810)	[1]	543	[1]	2,309	[2]	384	[1]
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax		0		0		(144)		(106)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit		0		0		56		41
Reclassification from Accumulated Other Comprehensive Income, net of tax		0	[1]	0	[1]	(88)	[2]	(65)	[1]
Other Comprehensive Income	[1]	(810)		543		2,221		319
Amortization of Net Retirement Plan Actuarial Loss [Member]
Schedule of Comprehensive Income [Line Items]
Other comprehensive income, before reclassifications, net of tax	[1]	0		0		0		0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax		181		192		503		579
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit		(70)		(75)		(189)		(227)
Reclassification from Accumulated Other Comprehensive Income, net of tax		111	[1]	117	[1]	314	[2]	352	[1]
Other Comprehensive Income	[1]	111		117		314		352
Accretion of Net Retirement Plan Prior Service Credit [Member]
Schedule of Comprehensive Income [Line Items]
Other comprehensive income, before reclassifications, net of tax	[1]	0		0		0		0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax		(3)		(13)		(7)		(41)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit		2		4		2		16
Reclassification from Accumulated Other Comprehensive Income, net of tax		(1)	[1]	(9)	[1]	(5)	[2]	(25)	[1]
Other Comprehensive Income	[1]	$ (1)		$ (9)		$ (5)		$ (25)

[1] All amounts are net of tax. Amounts in parentheses indicate debits.

[2] These accumulated other comprehensive income components are included in the computation of net periodic pension cost.