Accumulated Other Comprehensive Income (Loss) (AOCI Components Pre Post & Tax Effect) (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Before Tax:
Net Unrealized Gains (Losses) Arising During the Period	$ 236	$ (9,420)	$ 12,458	$ 12,804
Amortization of Unrealized Holding (Gains) Losses on HTM Securities	497	286	1,492	949
Net Unrealized Gains (Losses) on Investment Securities	733	(9,134)	13,950	13,753
Amortization of Net Actuarial Losses (Gains)	322	314	967	940
Amortization of Prior Service Credit	(81)	(81)	(242)	(242)
Defined Benefit Plans, Net	241	233	725	698
Other Comprehensive Income (Loss)	974	(8,901)	14,675	14,451
Other Comprehensive Income (Loss), Tax Effect:
Net Unrealized Gains (Losses) Arising During the Period	93	(3,719)	4,917	5,055
Amortization of Unrealized Holding (Gains) Losses on HTM Securities	196	113	589	375
Net Unrealized Gains (Losses) on Investment Securities	289	(3,606)	5,506	5,430
Amortization of Net Actuarial Losses (Gains)	127	124	382	371
Amortization of Prior Service Credit	(32)	(31)	(96)	(95)
Defined Benefit Plans, Net	95	93	286	276
Other Comprehensive Income (Loss)	384	(3,513)	5,792	5,706
Other Comprehensive Income (Loss), Net of Tax:
Net Unrealized Gains (Losses) Arising During the Period	143	(5,701)	7,541	7,749
Amortization of Unrealized Holding (Gains) Losses on HTM Securities	301	173	903	574
Net Unrealized Gains (Losses) on Investment Securities	444	(5,528)	8,444	8,323
Amortization of Net Actuarial Losses (Gains)	195	190	585	569
Amortization of Prior Service Credit	(49)	(50)	(146)	(147)
Defined Benefit Plans, Net	146	140	439	422
Total Other Comprehensive Income (Loss)	$ 590	$ (5,388)	$ 8,883	$ 8,745