Fair Value Measurement Of Assets And Liabilities (Schedule Of Gains And Losses From Fair Value Changes) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Gains and Losses from Fair Value Changes [Line Items]
Gains (Losses) on Change in Fair Value	$ 2,178	$ 6,166
Net Impairment Losses On Securities [Member] | Available For Sale Securities [Member]
Gains and Losses from Fair Value Changes [Line Items]
Gains (Losses) on Change in Fair Value		(825)
Trading (Losses) Gains, Net [Member] | Trading Securities [Member]
Gains and Losses from Fair Value Changes [Line Items]
Gains (Losses) on Change in Fair Value	252	493
Trading (Losses) Gains, Net [Member] | Junior Subordinated Debentures Issued To Capital Trusts [Member]
Gains and Losses from Fair Value Changes [Line Items]
Gains (Losses) on Change in Fair Value	(1,240)	2,889
Gains On Sales Of Loans, Net [Member] | Loans Held For Sale [Member]
Gains and Losses from Fair Value Changes [Line Items]
Gains (Losses) on Change in Fair Value	$ 3,166	$ 3,609