Fair Value Measurements (Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 202,476	$ 204,301
Total gains or losses (realized /unrealized), included in earnings	4,114	1,062
Total gains or losses (realized /unrealized), included in other comprehensive income	(5,458)	(1,271)
Investment securities called	(350)	(5,918)
Discount accretion	60	307
Purchase of private equity securities	3,275	179
Sale / paydown of private equity securities	(2,434)	43
Capitalized interest/dividends	177	79
Purchase of risk participation agreement	28
Sales of risk participation agreements		(76)
Ending balance	201,888	198,706
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	4,123	1,544
State And Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	135,621	150,089
Total gains or losses (realized /unrealized), included in other comprehensive income	(5,458)	(1,271)
Investment securities called	(350)	(5,918)
Discount accretion	60	307
Ending balance	129,873	143,207
Private Equity Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	66,978	53,860
Total gains or losses (realized /unrealized), included in earnings	4,125	1,425
Purchase of private equity securities	3,275	179
Sale / paydown of private equity securities	(2,434)	43
Capitalized interest/dividends	177
Ending balance	72,121	55,507
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	4,125	1,425
Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	(123)	352
Total gains or losses (realized /unrealized), included in earnings	(11)	(363)
Capitalized interest/dividends		79
Purchase of risk participation agreement	28
Sales of risk participation agreements		(76)
Ending balance	(106)	(8)
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ (2)	$ 119