Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 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		$ 14,406	$ (13,613)
Changes in fair value of available for sale debt securities, tax		3,385	(3,199)
Changes in fair value of available for sale debt securities		11,021	(10,414)
Net gains on debt securities reclassified into earnings, before tax		0	0
Net gains on debt securities reclassified into earnings, tax		0	0
Net gains on debt securities reclassified into earnings		0	0
Net change in fair value of available for sale debt securities, before tax		14,406	(13,613)
Net change in fair value of available for sale debt securities, tax		3,385	(3,199)
Net change in fair value of available for sale debt securities		11,021	(10,414)
Change in fair value of cash flow hedges, before tax		(546)	803
Change in fair value of cash flow hedges, tax		(128)	91
Change in fair value of cash flow hedges		(418)	712
Net cash flow hedge losses reclassified into earnings, before tax	[1]	(31)	231
Net cash flow hedge losses reclassified into earnings, tax	[1]	(7)	54
Net cash flow hedge losses reclassified into earnings	[1]	(24)	177
Net change in fair value of cash flow hedges, before tax		(577)	1,034
Net change in fair value of cash flow hedges, tax		(135)	145
Net change in fair value of cash flow hedges		(442)	889
Amortization of net actuarial losses, before tax	[2]	300	476
Amortization of net actuarial losses, tax	[2]	70	112
Amortization of net actuarial losses	[2]	230	364
Amortization of net prior service credits, before tax	[2]	(4)	(6)
Amortization of net prior service credits, tax	[2]	(1)	(2)
Amortization of net prior service credits	[2]	(3)	(4)
Net change in defined benefit plan obligations, before tax		296	470
Net change in defined benefit plan obligations, tax		69	110
Net change in defined benefit plan obligations		227	360
Total other comprehensive income (loss), before tax		14,125	(12,109)
Total other comprehensive income (loss), tax		3,319	(2,944)
Total other comprehensive income (loss), net of tax		$ 10,806	$ (9,165)

[1] 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.

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