Derivatives and Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	$ 53,158		$ 63,231		$ 66,619
Derivative Liability, Fair Value	62,217		77,968		85,803
Interest rate swaps [Member] | Designated as Hedging Instrument [Member]
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	4,632		0		0
Derivative Asset, Fair Value	0	[1]	0	[1]	0	[1]
Derivative Liability, Notional/Contract Amount	136,186		161,133		196,798
Derivative Liability, Fair Value	$ 14,319	[2]	$ 19,080	[2]	$ 23,229	[2]

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

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