Fair Value Measurements (Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 80,994	$ 151,836	$ 80,296	$ 152,501
Total gains or losses (realized /unrealized), included in earnings	(2,785)	(1,172)	(6,040)	3,396
Total gains or losses (realized /unrealized), included in other comprehensive income	317	227	819	(127)
Investment securities called	(1,100)	0	(1,200)	(2,000)
Discount accretion	12	22	94	173
Purchase of private equity securities	2,894	9,370	8,735	11,023
Sales And Repayments Of Private Equity Securities	(3,315)	0	(5,713)	(4,800)
Capitalized interest/dividends	15	0	77	117
Sale Of Risk Participation Agreement	(33)	0	(69)	0
Ending balance	76,999	160,283	76,999	160,283
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(1,995)	(827)	(5,677)	3,396
State And Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	17,679	92,940	17,195	95,143
Total gains or losses (realized /unrealized), included in earnings	0	0	0	0
Total gains or losses (realized /unrealized), included in other comprehensive income	317	227	819	(127)
Investment securities called	(1,100)	0	(1,200)	(2,000)
Discount accretion	12	22	94	173
Purchase of private equity securities	0	0	0	0
Sales And Repayments Of Private Equity Securities	0	0	0	0
Capitalized interest/dividends	0	0	0	0
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	16,908	93,189	16,908	93,189
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	62,813	58,726	63,032	57,581
Total gains or losses (realized /unrealized), included in earnings	(2,921)	(1,221)	(6,645)	2,954
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	2,894	9,370	8,735	11,023
Sales And Repayments Of Private Equity Securities	(3,315)	0	(5,713)	(4,800)
Capitalized interest/dividends	15	0	77	117
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	59,486	66,875	59,486	66,875
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(2,921)	(1,221)	(6,545)	2,954
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	502	170	69	(223)
Total gains or losses (realized /unrealized), included in earnings	136	49	605	442
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	0
Sales And Repayments Of Private Equity Securities	0	0	0	0
Capitalized interest/dividends	0	0	0	0
Sale Of Risk Participation Agreement	(33)	0	(69)	0
Ending balance	605	219	605	219
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 926	$ 394	$ 868	$ 442