Assets & Liability Derivative Positions & the Potential Effect of Netting Arrangements - Current Quarter (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 16,437	$ 16,697
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	16,437	16,697
Derivative, Collateral, Obligation to Return Securities	2,078	2,823
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	14,359	13,874
Derivative Liability, Fair Value, Gross Liability	203,647	225,648
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	203,647	225,648
Derivative, Collateral, Right to Reclaim Securities	2,078	2,823
Derivative, Collateral, Right to Reclaim Cash	(157,942)	(179,550)
Derivative Liability, Fair Value, Amount Offset Against Collateral	2,541	3,799
Interest Rate Swap [Member]
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	0	0
Derivative, Collateral, Obligation to Return Securities	0	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	0	0
Derivative Liability, Fair Value, Gross Liability	8,720	9,630
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	8,720	9,630
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	8,720	9,630
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Credit Default Swap [Member]
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	15,958	16,301
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	15,958	16,301
Derivative, Collateral, Obligation to Return Securities	2,078	2,823
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	13,880	13,478
Derivative Liability, Fair Value, Gross Liability	15,979	16,340
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	15,979	16,340
Derivative, Collateral, Right to Reclaim Securities	2,078	2,823
Derivative, Collateral, Right to Reclaim Cash	11,823	10,108
Derivative Liability, Fair Value, Amount Offset Against Collateral	2,078	3,409
Foreign Exchange Contract [Member]
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	479	396
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	479	396
Derivative, Collateral, Obligation to Return Securities	0	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	479	396
Derivative Liability, Fair Value, Gross Liability	463	390
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	463	390
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	463	390
Customer Repurchase Agreements [Domain]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	128,485	149,288
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	128,485	149,288
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	(128,485)	(149,288)
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Wholesale Repurchase Agreements [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	50,000	50,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	50,000	50,000
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	(50,000)	(50,000)
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 0	$ 0