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
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 100,307	$ 73,271
Total gains or losses (realized /unrealized), included in earnings	(1,527)	4,470
Total gains or losses (realized/unrealized) included in other comprehensive income (loss)	364	133
Discount accretion	7	9
Purchase of private equity securities	2,060	4,879
Sales And Repayments Of Private Equity Securities	0	(20)
Capitalized interest/dividends	0	35
Sale Of Risk Participation Agreement	0	(148)
Ending balance	101,211	82,629
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(991)	5,050
State and Municipal Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	14,158	17,016
Total gains or losses (realized /unrealized), included in earnings	0	0
Total gains or losses (realized/unrealized) included in other comprehensive income (loss)	364	133
Discount accretion	7	9
Purchase of private equity securities	0	0
Sales And Repayments Of Private Equity Securities	0	0
Capitalized interest/dividends	0	0
Sale Of Risk Participation Agreement	0	0
Ending balance	14,529	17,158
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
Private Equity Funds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	85,659	55,752
Total gains or losses (realized /unrealized), included in earnings	(1,842)	4,305
Total gains or losses (realized/unrealized) included in other comprehensive income (loss)	0	0
Discount accretion	0	0
Purchase of private equity securities	2,060	4,879
Sales And Repayments Of Private Equity Securities	0	(20)
Capitalized interest/dividends	0	35
Sale Of Risk Participation Agreement	0	0
Ending balance	85,877	64,951
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	(1,842)	4,305
Derivative Level Three Unobservable Inputs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	490	503
Total gains or losses (realized /unrealized), included in earnings	315	165
Total gains or losses (realized/unrealized) included in other comprehensive income (loss)	0	0
Discount accretion	0	0
Purchase of private equity securities	0	0
Sales And Repayments Of Private Equity Securities	0	0
Capitalized interest/dividends	0	0
Sale Of Risk Participation Agreement	0	(148)
Ending balance	805	520
Total gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end	$ 851	$ 745