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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 101,211	$ 82,629	$ 100,307	$ 73,271
Total gains or losses (realized /unrealized), included in earnings	(1,051)	3,955	(2,578)	8,425
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(5)	(379)	359	(246)
Investment Securities Sold	0	(1,715)	0	(1,715)
Investment Securities Called	(2,920)	0	(2,920)	0
Discount accretion	37	9	44	18
Purchase of private equity securities	7,829	364	9,889	5,243
Sales And Repayments Of Private Equity Securities	(6,150)	(166)	(6,150)	(186)
Capitalized interest/dividends	31	0	31	35
Purchase Of Risk Participation Agreement	26	0	26	0
Sale Of Risk Participation Agreement	(73)	0	(73)	(148)
Ending balance	98,935	84,697	98,935	84,697
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(214)	4,538	(3,478)	9,006
State and Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	14,529	17,158	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)	(5)	(379)	359	(246)
Investment Securities Sold	0	(1,715)	0	(1,715)
Investment Securities Called	(2,920)	0	(2,920)	0
Discount accretion	37	9	44	18
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	11,641	15,073	11,641	15,073
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	85,877	64,951	85,659	55,752
Total gains or losses (realized /unrealized), included in earnings	(1,176)	3,791	(3,018)	8,096
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	7,829	364	9,889	5,243
Sales And Repayments Of Private Equity Securities	(6,150)	(166)	(6,150)	(186)
Capitalized interest/dividends	31	0	31	35
Purchase Of Risk Participation Agreement	0	0	0	0
Sale Of Risk Participation Agreement	0	0	0	0
Ending balance	86,411	68,940	86,411	68,940
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(1,176)	3,791	(4,468)	8,096
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	805	520	490	503
Total gains or losses (realized /unrealized), included in earnings	125	164	440	329
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	26	0	26	0
Sale Of Risk Participation Agreement	(73)	0	(73)	(148)
Ending balance	883	684	883	684
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 962	$ 747	$ 990	$ 910