Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Change in fair value of securities available for sale, before tax		$ 8,784	$ 26,074		$ (12,063)
Change in fair value of securities available for sale, tax		2,129	6,127		(2,835)
Change is fair value of securities available for sale		6,655	19,947		(9,228)
Net (gains) losses on securities classified into earnings, before tax		0	53	[1]	0
Net (gains) losses on securities classified into earnings, tax		0	12	[1]	0
Net (gains) losses on securities classified into earnings		0	41	[1]	0
Net change in fair value of securities available for sale, before tax		8,784	26,127		(12,063)
Net change in fair value of securities available for sale, tax		2,129	6,139		(2,835)
Net change in fair value of available for sale debt securities		6,655	19,988		(9,228)
Net change in fair value of cash flow hedges, before tax		(2,003)	(1,444)		639
Net change in fair value of cash flow hedges, tax		(482)	(339)		151
Change in fair value of cash flow hedges		(1,521)	(1,105)		488
Net cash flow hedge losses reclassified into earnings, before tax	[2]	1,136	159		170
Net cash flow hedge losses reclassified into earnings, tax	[2]	269	38		39
Net cash flow hedge losses reclassified into earnings	[2]	867	121		131
Change in fair value of cash flow hedges, before tax		(867)	(1,285)		809
Change in fair value of cash flow hedges, tax		(213)	(301)		190
Net change in fair value of cash flow hedges		(654)	(984)		619
Defined benefit plan obligation adjustment, before tax		(5,093)	(3,710)		3,098
Defined benefit plan obligation adjustment, tax		(1,197)	(872)		729
Defined benefit plan obligation adjustment		(3,896)	(2,838)		2,369
Amortization of net actuarial losses, before tax	[3]	2,141	1,200		1,907
Amortization of net actuarial losses, tax	[3]	400	282		448
Amortization of net actuarial losses	[3]	1,741	918		1,459
Amortization of net prior service credits, before tax	[3]	0	(16)		(24)
Amortization of net prior service credits, tax	[3]	0	(4)		(6)
Prior service credit	[3]	0	(12)		(18)
Recognized in other comprehensive income (loss)		(2,952)	(2,526)		4,981
Net change in defined benefit plan obligations, tax		(797)	(594)		1,171
Net change in defined benefit plan obligations		(2,155)	(1,932)		3,810
Total other comprehensive income (loss), before tax		4,965	22,316		(6,273)
Total other comprehensive income (loss), tax		1,119	5,244		(1,474)
Total other comprehensive income (loss), net of tax		3,846	17,072		(4,799)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax		$ 6,655	$ 19,988		$ (9,228)

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

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