Bank Loans (Aging Of The Recorded Investment In Past Due Loans) (Details) - USD ($)		Jun. 30, 2023		Dec. 31, 2022
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 24,061,000		$ 12,612,000
Total		20,532,967,000		20,602,558,000
Non-Accrual		10,061,000	[1]	10,102,000	[2]
Restructured		148,000	[1]	150,000	[2]
Nonperforming loans with no allowance		1,211,000	[1]	0	[2]
Total		11,420,000	[1]	10,252,000	[2]
Loans past due 90 days and still accruing interest		0		0
30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		12,789,000		2,510,000
90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		11,272,000		10,102,000
Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		20,508,906,000		20,589,946,000
Residential Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		14,537,000		3,133,000
Total		7,708,506,000		7,371,671,000
Non-Accrual		1,032,000	[1]	870,000	[2]
Restructured		148,000	[1]	150,000	[2]
Nonperforming loans with no allowance		927,000	[1]	0	[2]
Total		2,107,000	[1]	1,020,000	[2]
Residential Real Estate [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		12,578,000		2,445,000
Residential Real Estate [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		1,959,000		688,000
Residential Real Estate [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		7,693,969,000		7,368,538,000
Commercial and Industrial [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		8,883,000		9,226,000
Total		4,471,031,000		4,897,176,000
Non-Accrual		8,883,000	[1]	9,226,000	[2]
Total		8,883,000	[1]	9,226,000	[2]
Commercial and Industrial [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		0		0
Commercial and Industrial [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		8,883,000		9,226,000
Commercial and Industrial [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		4,462,148,000		4,887,950,000
Fund Banking [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		4,349,541,000		4,182,641,000
Fund Banking [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		4,349,541,000		4,182,641,000
Securities-Based Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		2,399,328,000		2,724,551,000
Securities-Based Loans [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,399,328,000		2,724,551,000
Commercial Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Total		677,521,000		675,599,000
Commercial Real Estate [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Commercial Real Estate [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		677,521,000		675,599,000
Construction And Land [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Total		772,571,000		593,191,000
Construction And Land [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Construction And Land [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		772,571,000		593,191,000
Home Equity Lines Of Credit [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		587,000		211,000
Total		110,766,000		107,136,000
Non-Accrual	[1]	116,000
Nonperforming loans with no allowance	[1]	281,000
Total	[1]	397,000
Home Equity Lines Of Credit [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		190,000		29,000
Home Equity Lines Of Credit [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		397,000		182,000
Home Equity Lines Of Credit [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		110,179,000		106,925,000
Other [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		54,000		42,000
Total		43,703,000		50,593,000
Non-Accrual		30,000	[1]	6,000	[2]
Nonperforming loans with no allowance		3,000	[1]	0	[2]
Total		33,000	[1]	6,000	[2]
Other [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		21,000		36,000
Other [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		33,000		6,000
Other [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 43,649,000		$ 50,551,000

[1] There were no loans past due 90 days and still accruing interest at June 30, 2023.

[2] There were no loans past due 90 days and still accruing interest at December 31, 2022.