Derivatives and Hedging Activities (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2012
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	$ 53,839		$ 63,231		$ 70,270
Derivative Liability, Fair Value	65,506		77,968		87,161
Not Designated as Hedging Instrument
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,696,516		1,379,768		1,392,185
Derivative Asset, Fair Value	53,839	[1]	63,231	[1]	70,270	[1]
Derivative Liability, Notional/Contract Amount	1,726,203		1,391,595		1,364,744
Derivative Liability, Fair Value	52,217	[2]	58,888	[2]	65,090	[2]
Not Designated as Hedging Instrument | Interest rate swaps
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,546,228		1,204,835		1,166,765
Derivative Asset, Fair Value	51,044	[1]	58,769	[1]	62,796	[1]
Derivative Liability, Notional/Contract Amount	1,546,228		1,204,835		1,166,765
Derivative Liability, Fair Value	51,044	[2]	58,769	[2]	62,796	[2]
Not Designated as Hedging Instrument | Mortgage loan commitments
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	144,572		168,271		221,057
Derivative Asset, Fair Value	2,729	[1]	4,400	[1]	7,394	[1]
Derivative Liability, Notional/Contract Amount	0		0		0
Derivative Liability, Fair Value	0	[2]	0	[2]	0	[2]
Not Designated as Hedging Instrument | Forward sales contracts
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0		0		0
Derivative Asset, Fair Value	0	[1]	0	[1]	0	[1]
Derivative Liability, Notional/Contract Amount	68,581		124,017		144,849
Derivative Liability, Fair Value	1,081	[2]	62	[2]	2,223	[2]
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	[1]	0	[1]	0	[1]
Derivative Liability, Notional/Contract Amount	50,336		25,225		20,861
Derivative Liability, Fair Value	0	[2]	0	[2]	0	[2]
Not Designated as Hedging Instrument | Foreign Exchange
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	5,716		6,662		4,363
Derivative Asset, Fair Value	66	[1]	62	[1]	80	[1]
Derivative Liability, Notional/Contract Amount	6,295		6,026		4,371
Derivative Liability, Fair Value	92	[2]	57	[2]	71	[2]
Not Designated as Hedging Instrument | Other Contract
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0		0		0
Derivative Asset, Fair Value	0	[1]	0	[1]	0	[1]
Derivative Liability, Notional/Contract Amount	54,763		31,492		27,898
Derivative Liability, Fair Value	$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] (a) Included in Other Assets on the Consolidated Balance Sheet

[2] (b) Included in Other Liabilities on the Consolidated Balance Sheet