Derivatives and Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	$ 60,115		$ 62,056		$ 40,380
Derivative Liability, Fair Value	80,174		86,106		63,923
Interest rate swaps [Member] | Designated as Hedging Instrument [Member]
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0		819		0
Derivative Asset, Fair Value	0	[1]	0	[1]	0	[1]
Derivative Liability, Notional/Contract Amount	220,630		234,330		283,567
Derivative Liability, Fair Value	$ 23,786	[2]	$ 25,889	[2]	$ 24,465	[2]

[1] Included in Other Assets on the Consolidated Balance Sheets

[2] Included in Other Liabilities on the Consolidated Balance Sheets