Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains and losses on available for sale securities reclassified from AOCI before tax		$ 12,529	$ 147	$ 17,157	$ 5,273
Securities gains (losses)		12,529	147	17,157	5,273
Amortization of actuarial losses and prior service cost		(1,830)	(2,835)	(3,430)	(5,668)
Total before taxes		(1,882)	(2,887)	(3,534)	(5,773)
Amounts reclassified from accumulated other comprehensive income, net of tax		(6,573)	1,691	(8,411)	305
Unrealized gains and losses on available for sale securities reclassified from AOCI tax		(4,793)	(74)	(6,563)	(2,051)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		7,736	73	10,594	3,222
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax		(52)	(52)	(104)	(105)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax		719	1,123	1,351	2,246
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax		(1,163)	(1,764)	(2,183)	(3,527)
Unrealized Loss on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income, net of tax	[1]	0	0	0	0
Unrealized Gains on Investment Securities Available for Sale
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income, net of tax	[1]	(7,736)	(73)	(10,594)	(3,222)
Defined Benefit Pension Items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income, net of tax	[1]	$ 1,163	$ 1,764	$ 2,183	$ 3,527

[1] All amounts are net of tax.