Derivative Financial Instruments (Fair Value of Derivatives by Balance Sheet Location) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 5,190	$ 6,364
Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	7,335	9,762
Interest rate swap contracts [Member] | Derivatives Designated as Cash Flow Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	0
Interest rate swap contracts [Member] | Derivatives Designated as Cash Flow Hedging Instruments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	1,438	1,619
Commitments to originate fixed rate mortgage loans to be sold [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	1,666	2,513
Commitments to originate fixed rate mortgage loans to be sold [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	71	0
Commitments to sell fixed rate mortgage loans [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	149	0
Commitments to sell fixed rate mortgage loans [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	2,369	4,191
Interest rate swaps with customers [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	0
Interest rate swaps with customers [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	3,375	3,851
Mirror swaps with counterparties [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	0
Mirror swaps with counterparties [Member] | Derivatives not Designated as Hedging Instruments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 3,457	$ 3,952