Bank Loans (Activity in the Allowance for Credit Losses on Loans by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 140,061	$ 130,213	$ 139,308	$ 128,292
Provision	7,857	6,832	20,408	11,390
Charge-offs	(12,185)	(1,931)	(23,991)	(5,501)
Recoveries	1		9	933
Ending Balance	135,734	135,114	135,734	135,114
Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	92,294	65,887	92,698	67,077
Provision	4,872	10,708	16,274	12,155
Charge-offs	(12,185)	(241)	(23,991)	(3,811)
Recoveries				933
Ending Balance	84,981	76,354	84,981	76,354
Residential Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	11,172	12,507	11,061	13,855
Provision	2,595	(1,265)	2,706	(2,613)
Ending Balance	13,767	11,242	13,767	11,242
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	13,251	18,589	12,866	11,817
Provision	(397)	(2,210)	(12)	4,562
Ending Balance	12,854	16,379	12,854	16,379
Fund Banking [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	10,246	8,763	10,792	10,173
Provision	702	3,416	156	2,006
Ending Balance	10,948	12,179	10,948	12,179
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	9,366	20,689	8,057	21,386
Provision	(571)	(3,687)	738	(4,384)
Charge-offs		(1,690)		(1,690)
Ending Balance	8,795	15,312	8,795	15,312
Securities-Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	2,928	3,068	2,917	3,035
Provision	200	(255)	211	(222)
Ending Balance	3,128	2,813	3,128	2,813
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	170	246	317	371
Provision	490	116	343	(9)
Ending Balance	660	362	660	362
Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	634	464	600	578
Provision	(34)	9	(8)	(105)
Recoveries	1		9
Ending Balance	$ 601	$ 473	$ 601	$ 473