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, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		$ 179,274	$ 173,652	$ 177,614	$ 179,968
Total gains or losses (realized/unrealized), included in earnings		(7,428)	(5,605)	(20,205)	(16,946)
Total gains or losses (realized/unrealized), included in other comprehensive income	[1]	(2)	18	3	49
Investment Securities Called		0	0	0	(1,000)
Discount accretion		0	0	1	48
Purchase of private equity securities		375	0	11,322	10,756
Sales And Repayments Of Private Equity Securities		(15,139)	(13,342)	(37,103)	(40,834)
Capitalized interest/dividends		(12)	327	(118)	327
Ending balance		171,924	166,260	171,924	166,260
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		7,428	5,605	10,480	17,446
Gains (Losses) included in OCI Attributable to Change in Unrealized Gains (Losses) Relating to Assets Still Held, Total		(2)	17	3	27
State and municipal obligations [Member]
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		953	920	947	1,841
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]	(2)	18	3	49
Investment Securities Called		0	0	0	(1,000)
Discount accretion		0	0	1	48
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
Ending balance		951	938	951	938
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		(2)	17	3	27
Private Equity Investments [Member]
Fair Value Assets Measured on Recurring Basis [Roll Forward]
Beginning balance		178,321	172,732	176,667	178,127
Total gains or losses (realized/unrealized), included in earnings		(7,428)	(5,605)	(20,205)	(16,946)
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		375	0	11,322	10,756
Sales And Repayments Of Private Equity Securities		(15,139)	13,342	37,103	(40,834)
Capitalized interest/dividends		(12)	327	(118)	327
Ending balance		170,973	165,322	170,973	165,322
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		7,428	5,605	10,480	17,446
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.