Derivatives and Hedging Activities (Designated as Hedging Instruments, Notional Values, Contractual Amounts and Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	$ 98,549	$ 58,107	$ 72,573
Derivative Liability, Fair Value	78,621	52,745	65,447
Commercial Loan Swaps (FRAPS) | Designated as Hedging Instrument
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0	0	0
Derivative Asset, Fair Value	0	0	0
Derivative Liability, Notional/Contract Amount	52,821	55,689	89,591
Derivative Liability, Fair Value	3,238	3,536	6,063
Sub Debt Swap | Designated as Hedging Instrument
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	250,000	250,000	250,000
Derivative Asset, Fair Value	22,718	8,739	12,688
Derivative Liability, Notional/Contract Amount	0	0	0
Derivative Liability, Fair Value	0	0	0
Interest rate swaps | Designated as Hedging Instrument
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	250,000	250,000	250,000	$ 250,000
Derivative Asset, Fair Value	22,718	8,739	12,688
Derivative Liability, Notional/Contract Amount	52,821	55,689	89,591
Derivative Liability, Fair Value	3,238	3,536	6,063
Level 2
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	98,549	58,107	72,573
Derivative Liability, Fair Value	78,621	52,745	65,447
Level 2 | Interest rate swaps | Designated as Hedging Instrument
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	22,718	8,739	12,688
Derivative Liability, Fair Value	$ 3,238	$ 3,536	$ 6,063