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		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 193,207	$ 202,825	$ 202,476	$ 204,301
Total gains or losses (realized /unrealized), included in earnings	2,775	3,305	8,371	6,967
Total gains or losses (realized /unrealized), included in other comprehensive income	3,015	(1,028)	(1,923)	(2,639)
Investment securities called	(3,000)	(1,300)	(6,350)	(8,243)
Discount accretion	176	112	383	517
Purchase of private equity securities		75	3,275	3,314
Sale / paydown of private equity securities	(1,614)	(1,121)	(11,893)	(1,121)
Capitalized interest/dividends	118		310	44
Purchase of risk participation agreement			28	79
Sales of risk participation agreements	(68)		(68)	(351)
Ending balance	194,609	202,868	194,609	202,868
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	2,737	3,158	6,909	7,249
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	127,540	141,940	135,621	150,089
Total gains or losses (realized /unrealized), included in earnings	0	0	0	0
Total gains or losses (realized /unrealized), included in other comprehensive income	3,015	(1,028)	(1,923)	(2,639)
Investment securities called	(3,000)	(1,300)	(6,350)	(8,243)
Discount accretion	176	112	383	517
Purchase of private equity securities		0	0	0
Sale / paydown of private equity securities	0	0	0	0
Capitalized interest/dividends	0		0	0
Purchase of risk participation agreement			0	0
Sales of risk participation agreements	0		0	0
Ending balance	127,731	139,724	127,731	139,724
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	0	0	0	0
Private Equity Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	65,766	61,173	66,978	53,860
Total gains or losses (realized /unrealized), included in earnings	2,774	2,921	8,374	6,951
Total gains or losses (realized /unrealized), included in other comprehensive income	0	0	0	0
Investment securities called	0	0	0	0
Discount accretion	0	0	0	0
Purchase of private equity securities		75	3,275	3,314
Sale / paydown of private equity securities	(1,614)	(1,121)	(11,893)	(1,121)
Capitalized interest/dividends	118		310	44
Purchase of risk participation agreement			0	0
Sales of risk participation agreements	0		0	0
Ending balance	67,044	63,048	67,044	63,048
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	2,774	2,921	6,949	7,026
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	(99)	(288)	(123)	352
Total gains or losses (realized /unrealized), included in earnings	1	384	(3)	16
Total gains or losses (realized /unrealized), included in other comprehensive income	0	0	0	0
Investment securities called	0	0	0	0
Discount accretion	0	0	0	0
Purchase of private equity securities		0	0	0
Sale / paydown of private equity securities	0	0	0	0
Capitalized interest/dividends	0		0	0
Purchase of risk participation agreement			28	79
Sales of risk participation agreements	(68)		(68)	(351)
Ending balance	(166)	96	(166)	96
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ (37)	$ 237	$ (40)	$ 223