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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		$ 173,652	$ 163,587	$ 179,968	$ 149,390
Total gains or losses (realized /unrealized), included in earnings		5,605	14,050	16,946	37,133
Total gains or losses (realized/unrealized), included in other comprehensive income	[1]	18	40	49	(130)
Investment Securities Called		0	0	(1,000)	0
Discount accretion		0	2	48	4
Purchase of private equity securities		0	899	10,756	2,021
Sale/pay down of private equity investments		(13,342)	(423)	(40,834)	(10,263)
Capitalized interest/dividends		327	44	327	44
Ending balance		166,260	178,199	166,260	178,199
Total gains or losses for the annual period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end		5,605	14,050	17,446	37,083
Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total		17	40	27	(130)
State and municipal obligations [Member]
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		920	1,816	1,841	1,984
Total gains or losses (realized /unrealized), included in earnings		0	0	0	0
Total gains or losses (realized/unrealized), included in other comprehensive income	[1]	18	40	49	(130)
Investment Securities Called		0	0	(1,000)	0
Discount accretion		0	2	48	4
Purchase of private equity securities		0	0	0	0
Sale/pay down of private equity investments		0	0	0	0
Capitalized interest/dividends		0	0	0	0
Ending balance		938	1,858	938	1,858
Total gains or losses for the annual period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end		0	0	0	0
Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total		17	40	27	(130)
Private Equity Investments [Member]
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		172,732	161,771	178,127	147,406
Total gains or losses (realized /unrealized), included in earnings		5,605	14,050	16,946	37,133
Total gains or losses (realized/unrealized), included in other comprehensive income	[1]	0	0	0	0
Investment Securities Called		0	0	0	0
Discount accretion		0	0	0	0
Purchase of private equity securities		0	899	10,756	2,021
Sale/pay down of private equity investments		(13,342)	(423)	(40,834)	(10,263)
Capitalized interest/dividends		(327)	44	327	44
Ending balance		165,322	176,341	165,322	176,341
Total gains or losses for the annual period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at period end		5,605	14,050	17,446	37,083
Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total		$ 0	$ 0	$ 0	$ 0

[1] * Included in "net unrealized gains (losses) on available for sale debt securities" in the consolidated statements of comprehensive income.