Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Changes in fair value of available for sale debt securities, before tax		$ 3,772	$ (5,924)	$ 25,985	$ (23,605)
Changes in fair value of available for sale debt securities, tax		886	(1,393)	6,106	(5,548)
Changes in fair value of available for sale debt securities		2,886	(4,531)	19,879	(18,057)
Net gains (losses) on debt securities reclassified into earnings, before tax	[1]	0	0	(80)	0
Net gains (losses) on debt securities reclassified into earnings, tax	[1]	0	0	(19)	0
Net gains (losses) on debt securities reclassified into earnings	[1]	0	0	(61)	0
Net change in fair value of available for sale debt securities, before tax		3,772	(5,924)	26,065	(23,605)
Net change in fair value of available for sale debt securities, tax		886	(1,393)	6,125	(5,548)
Net change in fair value of available for sale debt securities		2,886	(4,531)	19,940	(18,057)
Change in fair value of cash flow hedges, before tax		(283)	(626)	(1,653)	632
Change in fair value of cash flow hedges, tax		(66)	(148)	(388)	50
Change in fair value of cash flow hedges		(217)	(478)	(1,265)	582
Net cash flow hedge losses reclassified into earnings, before tax	[2]	60	830	39	1,082
Net cash flow hedge losses reclassified into earnings, tax	[2]	14	197	9	255
Net cash flow hedge losses reclassified into earnings	[2]	46	633	30	827
Net change in fair value of cash flow hedges, before tax		(223)	204	(1,614)	1,714
Net change in fair value of cash flow hedges, tax		(52)	49	(379)	305
Net change in fair value of cash flow hedges		(171)	155	(1,235)	1,409
Amortization of net actuarial losses, before tax	[3]	300	477	900	1,430
Amortization of net actuarial losses, tax	[3]	70	112	211	337
Amortization of net actuarial losses	[3]	230	365	689	1,093
Amortization of net prior service credits, before tax	[3]	(4)	(6)	(12)	(17)
Amortization of net prior service credits, tax	[3]	(1)	(2)	(3)	(5)
Amortization of net prior service credits	[3]	(3)	(4)	(9)	(12)
Net change in defined benefit plan obligations, before tax		296	471	888	1,413
Net change in defined benefit plan obligations, tax		69	110	208	332
Net change in defined benefit plan obligations		227	361	680	1,081
Total other comprehensive income (loss), before tax		3,845	(5,249)	25,339	(20,478)
Total other comprehensive income (loss), tax		903	(1,234)	5,954	(4,911)
Total other comprehensive income (loss), net of tax		$ 2,942	$ (4,015)	$ 19,385	$ (15,567)

[1] The pre-tax amount is reported as net realized losses on securities in the Unaudited Consolidated Statements of Income.

[2] The pre-tax amounts are included in interest expense on FHLB advances, interest expense on junior subordinated debentures and interest and fees on loans in the Unaudited Consolidated Statements of Income.

[3] The pre-tax amounts are included in other expenses in the Unaudited Consolidated Statements of Income.