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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 98,935	$ 84,697	$ 100,307	$ 73,271
Total gains or losses (realized /unrealized), included in earnings	1,945	4,217	(633)	12,642
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(65)	167	294	(79)
Investment Securities Sold	0	(518)	0	(2,233)
Investment Securities Called	(1,715)	0	(4,635)	0
Discount accretion	36	7	80	25
Purchase of private equity securities	5,010	10,407	14,899	15,650
Sales And Repayments Of Private Equity Securities	0	0	(6,150)	(186)
Capitalized interest/dividends	0	0	31	35
Purchase Of Risk Participation Agreement	200	50	226	50
Sale Of Risk Participation Agreement	(241)	(31)	(314)	(179)
Ending balance	104,105	98,996	104,105	98,996
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	2,880	4,947	(1,532)	13,223
State and Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	11,641	15,073	14,158	17,016
Total gains or losses (realized /unrealized), included in earnings	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(65)	167	294	(79)
Investment Securities Sold	0	(518)	0	(2,233)
Investment Securities Called	(1,715)	0	(4,635)	0
Discount accretion	36	7	80	25
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
Purchase Of Risk Participation Agreement	0	0	0	0
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	9,897	14,729	9,897	14,729
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	86,411	68,940	85,659	55,752
Total gains or losses (realized /unrealized), included in earnings	2,020	4,275	(998)	12,371
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Investment Securities Sold	0	0	0	0
Investment Securities Called	0	0	0	0
Discount accretion	0	0	0	0
Purchase of private equity securities	5,010	10,407	14,899	15,650
Sales And Repayments Of Private Equity Securities	0	0	(6,150)	(186)
Capitalized interest/dividends	0	0	31	35
Purchase Of Risk Participation Agreement	0	0	0	0
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	93,441	83,622	93,441	83,622
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	2,020	4,275	(2,448)	12,371
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	883	684	490	503
Total gains or losses (realized /unrealized), included in earnings	(75)	(58)	365	271
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Investment Securities Sold	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
Purchase Of Risk Participation Agreement	200	50	226	50
Sale Of Risk Participation Agreement	(241)	(31)	(314)	(179)
Ending balance	767	645	767	645
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 860	$ 672	$ 916	$ 852