Bank Loans (Aging Of The Recorded Investment In Past Due Loans) (Details) - USD ($)		Dec. 31, 2023		Dec. 31, 2022
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 22,043,000		$ 12,612,000
Total		19,441,467,000		20,602,558,000
Non-accrual		42,221,000	[1]	10,102,000	[2]
Restructured		145,000	[1]	150,000	[2]
Nonperforming loans with no allowance		3,090,000	[1]	0	[2]
Total		45,456,000	[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		15,927,000		2,510,000
90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		6,116,000		10,102,000
Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		19,419,424,000		20,589,946,000
Residential Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		19,257,000		3,133,000
Total		8,047,647,000		7,371,671,000
Non-accrual		2,945,000	[1]	870,000	[2]
Restructured		145,000	[1]	150,000	[2]
Nonperforming loans with no allowance		1,000,000	[1]	0	[2]
Total		4,090,000	[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		15,312,000		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		3,945,000		688,000
Residential Real Estate [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		8,028,390,000		7,368,538,000
Fund Banking [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		3,633,126,000		4,182,641,000
Fund Banking [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		3,633,126,000		4,182,641,000
Commercial and Industrial [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,022,000		9,226,000
Total		3,566,987,000		4,897,176,000
Non-accrual	[2]			9,226,000
Nonperforming loans with no allowance	[1]	2,022,000
Total		2,022,000	[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
Commercial and Industrial [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,022,000		9,226,000
Commercial and Industrial [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		3,564,965,000		4,887,950,000
Securities-Based Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		3,000
Total		2,306,455,000		2,724,551,000
Nonperforming loans with no allowance	[1]	3,000
Total	[1]	3,000
Securities-Based Loans [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		3,000
Securities-Based Loans [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,306,452,000		2,724,551,000
Construction And Land [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		1,034,370,000		593,191,000
Construction And Land [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		1,034,370,000		593,191,000
Commercial Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Total		660,631,000		675,599,000
Non-accrual	[1]	39,195,000
Total	[1]	39,195,000
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		660,631,000		675,599,000
Home Equity Lines Of Credit [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		657,000		211,000
Total		136,270,000		107,136,000
Non-accrual	[1]	22,000
Nonperforming loans with no allowance	[1]	65,000
Total	[1]	87,000
Home Equity Lines Of Credit [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		570,000		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		87,000		182,000
Home Equity Lines Of Credit [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		135,613,000		106,925,000
Other [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		104,000		42,000
Total		55,981,000		50,593,000
Non-accrual		59,000	[1]	6,000	[2]
Nonperforming loans with no allowance	[2]			0
Total		59,000	[1]	6,000	[2]
Other [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		45,000		36,000
Other [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		59,000		6,000
Other [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 55,877,000		$ 50,551,000

[1] There were no loans past due 90 days and still accruing interest at December 31, 2023.

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