Derivative Instruments (Schedule of Notional Amounts of Derivative Instruments) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Interest Rate Swaps [Member]
Notional Amount of Derivatives	$ 531,487	$ 498,071
Interest Rate Caps [Member]
Notional Amount of Derivatives	30,736	31,736
Credit Risk Participation Agreements [Member]
Notional Amount of Derivatives	83,101	40,661
Foreign Exchange (Forward Contracts) [Member]
Notional Amount of Derivatives	64,581	25,867
Foreign Exchange (Option Contracts) [Member]
Notional Amount of Derivatives	3,100
Mortgage Loan Commitments [Member]
Notional Amount of Derivatives	8,241	12,125
Mortgage Loan Forward Sale Contracts [Member]
Notional Amount of Derivatives	13,349	24,112
Total Notional Amount [Member]
Notional Amount of Derivatives	$ 734,595	$ 632,572