Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 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		$ 7,807	$ (4,068)	$ 22,213	$ (17,681)
Changes in fair value of available for sale debt securities, tax		1,835	(956)	5,220	(4,155)
Changes in fair value of available for sale debt securities		5,972	(3,112)	16,993	(13,526)
Net gains (losses) on debt securities reclassified into earnings, before tax	[1]	(80)	0	(80)	0
Net gains (losses) on debt securities reclassified into earnings, tax	[1]	(19)	0	(19)	0
Net gains (losses) on debt securities reclassified into earnings	[1]	(61)	0	(61)	0
Net change in fair value of available for sale debt securities, before tax		7,887	(4,068)	22,293	(17,681)
Net change in fair value of available for sale debt securities, tax		1,854	(956)	5,239	(4,155)
Net change in fair value of available for sale debt securities		6,033	(3,112)	17,054	(13,526)
Change in fair value of cash flow hedges, before tax		(824)	455	(1,370)	1,258
Change in fair value of cash flow hedges, tax		(194)	107	(322)	198
Change in fair value of cash flow hedges		(630)	348	(1,048)	1,060
Net cash flow hedge losses reclassified into earnings, before tax	[2]	10	21	(21)	252
Net cash flow hedge losses reclassified into earnings, tax	[2]	2	4	(5)	58
Net cash flow hedge losses reclassified into earnings	[2]	8	17	(16)	194
Net change in fair value of cash flow hedges, before tax		(814)	476	(1,391)	1,510
Net change in fair value of cash flow hedges, tax		(192)	111	(327)	256
Net change in fair value of cash flow hedges		(622)	365	(1,064)	1,254
Amortization of net actuarial losses, before tax	[3]	300	477	600	953
Amortization of net actuarial losses, tax	[3]	71	113	141	225
Amortization of net actuarial losses	[3]	229	364	459	728
Amortization of net prior service credits, before tax	[3]	(4)	(5)	(8)	(11)
Amortization of net prior service credits, tax	[3]	(1)	(1)	(2)	(3)
Amortization of net prior service credits	[3]	(3)	(4)	(6)	(8)
Net change in defined benefit plan obligations, before tax		296	472	592	942
Net change in defined benefit plan obligations, tax		70	112	139	222
Net change in defined benefit plan obligations		226	360	453	720
Total other comprehensive income (loss), before tax		7,369	(3,120)	21,494	(15,229)
Total other comprehensive income (loss), tax		1,732	(733)	5,051	(3,677)
Total other comprehensive income (loss), net of tax		$ 5,637	$ (2,387)	$ 16,443	$ (11,552)

[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.