Accumulated Other Comprehensive Loss (Components of AOCI) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (52,981)	$ (25,268)
Other comprehensive income (loss) before reclassifications		(11,378)	(13,115)
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	(81)	(14,598)
Net current period other comprehensive (loss) income		(11,459)	(27,713)	$ 56,838
Ending balance		(64,440)	(52,981)	(25,268)
Unrealized Loss on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[2]	(2,664)	(4,434)
Other comprehensive income (loss) before reclassifications	[2]	1,772	1,770
Amounts reclassified from accumulated other comprehensive (loss) income	[2]	0	0
Net current period other comprehensive (loss) income	[2]	1,772	1,770
Ending balance	[2]	(892)	(2,664)	(4,434)
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[2]	5,098	(10,091)
Other comprehensive income (loss) before reclassifications	[2]	(13,544)	33,061
Amounts reclassified from accumulated other comprehensive (loss) income	[1],[2]	(6,679)	(17,872)
Net current period other comprehensive (loss) income	[2]	(20,223)	15,189
Ending balance	[2]	(15,125)	5,098	(10,091)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[2]	(55,415)	(10,743)
Other comprehensive income (loss) before reclassifications	[2]	394	(47,946)
Amounts reclassified from accumulated other comprehensive (loss) income	[1],[2]	6,598	3,274
Net current period other comprehensive (loss) income	[2]	6,992	(44,672)
Ending balance	[2]	$ (48,423)	$ (55,415)	$ (10,743)

[1] (Dollars in thousands) Year ended December 31, 2015Details about accumulated other comprehensive income (loss) Amount reclassified from accumulated other comprehensive income (loss)(1) Affected line item in the statement where net income is presentedUnrealized gains and losses on available for sale securities $10,817 Securities gains (4,138) Income taxes $6,679 Net income Amortization of defined benefit pension items Prior service costs $(210) Employee benefitsActuarial losses (11,376) Employee benefits (11,586) Employee benefits 4,988 Income taxes $(6,598) Net incomeTotal reclassifications for the period $81 Year ended December 31, 2014Details about accumulated other comprehensive income (loss) Amount reclassified from accumulated other comprehensive income (loss)(1) Affected line item in the statement where net income is presentedUnrealized gains and losses on available for sale securities $29,096 Securities gains (11,224) Income taxes $17,872 Net income Amortization of defined benefit pension items Prior service costs $(210) Employee benefitsActuarial losses (5,148) Employee benefits (5,358) Employee benefits 2,084 Income taxes $(3,274) Net incomeTotal reclassifications for the period $14,598 (1) Amounts in parentheses indicate debits to profit/loss.

[2] All amounts are net of tax. Amounts in parentheses indicate debits.