Allowance For Loan Losses, Allowance For Losses On Lending-Related Commitments And Impaired Loans (Narrative) (Details) (USD $)	3 Months Ended				9 Months Ended				12 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Allowance For Loan Losses, Allowance For Losses On Lending-Related Commitments And Impaired Loans
Financing Receivable, Modifications, Recorded Investment	$ 104,392,000		$ 93,666,000		$ 104,392,000		$ 93,666,000		$ 104,392,000	$ 93,666,000	$ 101,190,000
Number of credit relationships in modified loans	136				136				136
Collateral impairment reviewed in restructured loan					6,300,000
Troubled Debt Restructuring Modifications Recorded Investment	13,473,000	[1]	24,074,000	[1]	55,976,000	[1]	80,031,000	[1]	73,838,000	112,463,000
Troubled Debt Restructuring Modifications Number Of Count	26	[1]	31	[1]	70	[1]	91	[1]	91	132
Weighted average stated interest rate - basis points	201		153		201		176
Principal balances that were forgiven	0		1,200,000		67,000		5,700,000
Restructured modified loans	$ 104,400,000				$ 104,400,000				$ 104,400,000

[1] Restructured loans may have more than one modification representing a concession. As such, restructured loans during the period may be represented in more than one of the categories noted above.