Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ (32,616)
Personnel expense	(101,398)	$ (100,152)
Interest income (Amortization of net unrealized gains on available for sale securities transferred to held to maturity securities)	(1,572)	0
Total other comprehensive income (loss)	34,783	29,650
Ending Balance	2,167
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(32,616)	(4,850)
Other comprehensive income (loss) before reclassifications	60,422	47,418
Investment securities gain, net	(3,098)
Personnel expense	495	545
Interest income (Amortization of net unrealized gains on available for sale securities transferred to held to maturity securities)	(1,572)
Income tax (expense) benefit	(21,464)	(18,313)
Total other comprehensive income (loss)	34,783	29,650
Ending Balance	2,167	24,800
Investment Securities Available For Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	459	18,512
Other comprehensive income (loss) before reclassifications	60,422	47,418
Investment securities gain, net	(3,098)
Personnel expense	0	0
Interest income (Amortization of net unrealized gains on available for sale securities transferred to held to maturity securities)	(1,572)
Income tax (expense) benefit	(21,275)	(18,105)
Total other comprehensive income (loss)	34,477	29,313
Ending Balance	34,936	47,825
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(33,075)	(23,362)
Other comprehensive income (loss) before reclassifications	0	0
Investment securities gain, net	0
Personnel expense	495	545
Interest income (Amortization of net unrealized gains on available for sale securities transferred to held to maturity securities)	0
Income tax (expense) benefit	(189)	(208)
Total other comprehensive income (loss)	306	337
Ending Balance	$ (32,769)	$ (23,025)

Accumulated Other Comprehensive Income (Loss) [Roll Forward]

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- Definition

Amortization of Net Unrealized Gain on Available-for-Sale Securities Transfered to Held-to-maturity Securities

+ References

No definition available.

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- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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- Definition

The aggregate amount of expenditures for salaries, wages, profit sharing and incentive compensation, and other employee benefits, including equity-based compensation, and pension and other postretirement benefit expense.

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Amount before tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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