Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Changes in fair value of available for sale debt securities, before tax		$ (4,582)	$ 3,772	$ 9,794	$ 25,985
Changes in fair value of available for sale debt securities, tax		(1,077)	886	2,301	6,106
Changes in fair value of available for sale debt securities		(3,505)	2,886	7,493	19,879
Net gains (losses) on debt securities reclassified into earnings, before tax	[1]	0	0	0	80
Net gains (losses) on debt securities reclassified into earnings, tax	[1]	0	0	0	19
Net gains (losses) on debt securities reclassified into earnings	[1]	0	0	0	61
Net change in fair value of available for sale debt securities, before tax		(4,582)	3,772	9,794	26,065
Net change in fair value of available for sale debt securities, tax		(1,077)	886	2,301	6,125
Net change in fair value of available for sale debt securities		(3,505)	2,886	7,493	19,940
Change in fair value of cash flow hedges, before tax		(146)	(283)	(1,994)	(1,653)
Change in fair value of cash flow hedges, tax		(39)	(66)	(473)	(388)
Change in fair value of cash flow hedges		(107)	(217)	(1,521)	(1,265)
Net cash flow hedge losses reclassified into earnings, before tax	[2]	344	60	829	39
Net cash flow hedge losses reclassified into earnings, tax	[2]	83	14	196	9
Net cash flow hedge losses reclassified into earnings	[2]	261	46	633	30
Net change in fair value of cash flow hedges, before tax		198	(223)	(1,165)	(1,614)
Net change in fair value of cash flow hedges, tax		44	(52)	(277)	(379)
Net change in fair value of cash flow hedges		154	(171)	(888)	(1,235)
Amortization of net actuarial losses, before tax	[3]	535	300	1,606	900
Amortization of net actuarial losses, tax	[3]	125	70	377	211
Amortization of net actuarial losses	[3]	410	230	1,229	689
Amortization of net prior service credits, before tax	[3]	0	(4)	0	(12)
Amortization of net prior service credits, tax	[3]	0	(1)	0	(3)
Amortization of net prior service credits	[3]	0	(3)	0	(9)
Net change in defined benefit plan obligations, before tax		535	296	1,606	888
Net change in defined benefit plan obligations, tax		125	69	377	208
Net change in defined benefit plan obligations		410	227	1,229	680
Total other comprehensive income (loss), before tax		(3,849)	3,845	10,235	25,339
Total other comprehensive income (loss), tax		(908)	903	2,401	5,954
Total other comprehensive income (loss), net of tax		$ (2,941)	$ 2,942	$ 7,834	$ 19,385

[1] The pre-tax amount is reported in 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.