Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Changes in fair value of securities available for sale, before tax		$ (13,613)	$ 636
Changes in fair value of securities available for sale, tax		(3,199)	235
Changes in fair value of securities available for sale		(10,414)	401
Net gains on securities reclassified into earnings, before tax		0	0
Net gains on securities reclassified into earnings, tax		0	0
Net gains on securities reclassified into earnings		0	0
Net change in fair value of securities available for sale, before tax		(13,613)	636
Net change in fair value of securities available for sale, tax		(3,199)	235
Net change in fair value of securities available for sale		(10,414)	401
Change in fair value of cash flow hedges, before tax		803	26
Change in fair value of cash flow hedges, tax		91	14
Change in fair value of cash flow hedges		712	12
Net cash flow hedge losses reclassified into earnings, before tax	[1]	231	136
Net cash flow hedge losses reclassified into earnings, tax	[1]	54	50
Net cash flow hedge losses reclassified into earnings	[1]	177	86
Net change in fair value of cash flow hedges, before tax		1,034	162
Net change in fair value of cash flow hedges, tax		145	64
Net change in fair value of cash flow hedges		889	98
Defined benefit plan obligation adjustment, before tax		0	0
Defined benefit plan obligation adjustment, tax		0	0
Defined benefit plan obligation adjustment		0	0
Amortization of net actuarial losses, before tax	[2]	476	344
Amortization of net actuarial losses, tax	[2]	112	127
Amortization of net actuarial losses	[2]	364	217
Amortization of net prior service credits, before tax	[2]	(6)	(6)
Amortization of net prior service credits, tax	[2]	(2)	(2)
Amortization of net prior service credits	[2]	(4)	(4)
Net change in defined benefit plan obligations, before tax		470	338
Net change in defined benefit plan obligations, tax		110	125
Net change in defined benefit plan obligations		360	213
Total other comprehensive income (loss), before tax		(12,109)	1,136
Total other comprehensive income (loss), tax		(2,944)	424
Total other comprehensive income (loss), net of tax		$ (9,165)	$ 712

[1] The pre-tax amounts are included in interest expense on Federal Home Loan Bank 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.