Other Comprehensive Income (Loss) (Activity in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Change in fair value of securities available for sale, before tax		$ 986		$ (12,502)		$ (4,926)
Change in fair value of securities available for sale, tax		365		(4,626)		(1,755)
Change is fair value of securities available for sale		621		(7,876)		(3,171)
Net (gains) losses on securities classified into earnings, before tax		0		0		0
Net (gains) losses on securities classified into earnings, tax		0		0		0
Net (gains) losses on securities classified into earnings		0		0		0
Net change in fair value of securities available for sale, before tax		986		(12,502)		(4,926)
Net change in fair value of securities available for sale, tax		365		(4,626)		(1,755)
Net change in fair value of securities available for sale		621		(7,876)		(3,171)
Net change in fair value of cash flow hedges, before tax		(774)		(403)		(102)
Net change in fair value of cash flow hedges, tax		(223)		(146)		(49)
Change in fair value of cash flow hedges		(551)		(257)		(53)
Net cash flow hedge losses reclassified into earnings, before tax		792	[1]	0	[1]	469	[2]
Net cash flow hedge losses reclassified into earnings, tax		293	[1]	0	[1]	172	[2]
Net cash flow hedge losses reclassified into earnings		499	[1]	0	[1]	297	[2]
Change in fair value of cash flow hedges, before tax		18		(403)		367
Change in fair value of cash flow hedges, tax		70		(146)		123
Net change in fair value of cash flow hedges		(52)		(257)		244
Defined benefit plan obligation adjustment, before tax		(1,591)		(4,106)		1,478
Defined benefit plan obligation adjustment, tax		(594)		(1,518)		376
Defined benefit plan obligation adjustment		(997)		(2,588)		1,102
Amortization of net actuarial losses, before tax	[3]	1,461		1,075		1,494
Amortization of net actuarial losses, tax	[3]	546		397		542
Amortization of net actuarial losses	[3]	915		678		952
Amortization of net prior service credits, before tax	[3]	(24)		(24)		(24)
Amortization of net prior service credits, tax	[3]	(9)		(9)		(7)
Amortization of net prior service credits	[3]	(15)		(15)		(17)
Net change in defined benefit plan obligations, before tax		(154)		(3,055)		2,948
Net change in defined benefit plan obligations, tax		(57)		(1,130)		911
Net change in defined benefit plan obligations		(97)		(1,925)		2,037
Total other comprehensive income (loss), before tax		850		(15,960)		(1,611)
Total other comprehensive income (loss), tax		378		(5,902)		(721)
Total other comprehensive income (loss), net of tax		472		(10,058)		(890)
Net Unrealized Gains on AFS Securities [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Total other comprehensive income (loss), net of tax		$ 621		$ (7,876)		$ (3,171)

[1] The pre-tax amounts are included in interest expense on Federal Home Loan Bank advances, interest expense on junior subordinated debentures and interest income and fees on loans in the Consolidated Statements of Income.

[2] The pre-tax amount is included in interest expense on junior subordinated debentures in the Consolidated Statements of Income.

[3] The pre-tax amount is included in salaries and employee benefits expense in the Consolidated Statements of Income.