Bank Loans (Risk Category Of Loan Portfolio) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	$ 20,532,967	$ 20,602,558
Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	20,258,507	20,427,527
Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	78,007	108,027
Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	186,517	56,899
Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	9,936	10,105
Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	7,708,506	7,371,671
Residential Real Estate [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	7,706,547	7,370,717
Residential Real Estate [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	312	266
Residential Real Estate [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	927
Residential Real Estate [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	720	688
Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	4,471,031	4,897,176
Commercial and Industrial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	4,298,705	4,743,290
Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	17,619	87,761
Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	145,824	56,899
Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	8,883	9,226
Fund Banking [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	4,349,541	4,182,641
Fund Banking [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	4,349,541	4,182,641
Securities-Based Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	2,399,328	2,724,551
Securities-Based Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	2,399,325	2,724,548
Securities-Based Loans [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Securities-Based Loans [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Securities-Based Loans [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	3	3
Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	677,521	675,599
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	577,777	655,599
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	60,000	20,000
Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	39,744
Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Construction And Land [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	772,571	593,191
Construction And Land [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	772,571	593,191
Construction And Land [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Construction And Land [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Construction And Land [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Home Equity Lines Of Credit [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	110,766	107,136
Home Equity Lines Of Credit [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	110,369	106,954
Home Equity Lines Of Credit [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	65
Home Equity Lines Of Credit [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	22
Home Equity Lines Of Credit [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	310	182
Other [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	43,703	50,593
Other [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	43,672	50,587
Other [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	11
Other [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0
Other [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	$ 20	$ 6