Derivatives and Hedging Activities (Not Designated as Hedging Instruments, Notional Values, Contractual Amounts and Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	$ 117,842	$ 58,107	$ 48,073
Derivative Liability, Fair Value	90,622	52,745	51,497
Not Designated as Hedging Instrument
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,957,441	1,858,882	1,823,511
Derivative Asset, Fair Value	88,082	49,368	46,920
Derivative Liability, Notional/Contract Amount	2,041,068	1,956,287	1,847,653
Derivative Liability, Fair Value	87,850	49,209	46,393
Not Designated as Hedging Instrument | Interest rate swaps
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,904,459	1,824,576	1,726,600
Derivative Asset, Fair Value	87,575	48,920	46,216
Derivative Liability, Notional/Contract Amount	1,904,459	1,824,576	1,726,600
Derivative Liability, Fair Value	87,575	48,920	46,216
Not Designated as Hedging Instrument | Mortgage loan commitments
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	32,802	20,635	52,024
Derivative Asset, Fair Value	253	149	342
Derivative Liability, Notional/Contract Amount	0	0	0
Derivative Liability, Fair Value	0	0	0
Not Designated as Hedging Instrument | Forward sales contracts
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0	0	15,200
Derivative Asset, Fair Value		0	106
Derivative Liability, Notional/Contract Amount	8,059	9,659	0
Derivative Liability, Fair Value	61	5	0
Not Designated as Hedging Instrument | Credit Risk Contract
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0	0	0
Derivative Asset, Fair Value	0	0	0
Derivative Liability, Notional/Contract Amount	74,945	73,715	73,512
Derivative Liability, Fair Value	7	0	0
Not Designated as Hedging Instrument | Equity Swap
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0	0	0
Derivative Asset, Fair Value	0	0	0
Derivative Liability, Notional/Contract Amount	35,034	36,631	31,718
Derivative Liability, Fair Value	0	0	0
Not Designated as Hedging Instrument | Foreign Exchange
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	20,180	13,671	29,687
Derivative Asset, Fair Value	254	299	256
Derivative Liability, Notional/Contract Amount	18,571	11,706	15,823
Derivative Liability, Fair Value	207	284	177
Level 2
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	117,842	58,107	48,073
Derivative Liability, Fair Value	90,622	52,745	51,497
Level 2 | Not Designated as Hedging Instrument
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	0
Level 2 | Not Designated as Hedging Instrument | Interest rate swaps
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	87,575	48,920	46,216
Derivative Liability, Fair Value	87,575	48,920	46,216
Level 2 | Not Designated as Hedging Instrument | Mortgage loan commitments
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	253	149	342
Level 2 | Not Designated as Hedging Instrument | Forward sales contracts
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value			106
Derivative Liability, Fair Value	61	5
Level 2 | Not Designated as Hedging Instrument | Credit Risk Contract
Derivatives not designated in hedge relationships
Derivative Liability, Fair Value	7
Level 2 | Not Designated as Hedging Instrument | Foreign Exchange
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	254	299	256
Derivative Liability, Fair Value	$ 207	$ 284	$ 177