Bank Loans (Risk Category Of Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	$ 20,819,250	$ 16,743,487
Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	20,579,965	16,553,018
Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	146,919	54,817
Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	81,346	127,831
Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	11,020	7,821
Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	7,048,762	5,482,026
Residential Real Estate [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	7,046,822	5,480,693
Residential Real Estate [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	150
Residential Real Estate [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	0	84
Residential Real Estate [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	1,790	1,249
Commercial and Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	9,394,557	7,345,753
Commercial and Industrial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	9,254,217	7,193,435
Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	69,769	38,000
Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	61,346	107,747
Commercial and Industrial [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	9,225	6,571
Securities-Based Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	2,785,679	2,880,158
Securities-Based Loans [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	2,785,676	2,880,158
Securities-Based Loans [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	3
Commercial Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	872,010	409,847
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	775,010	407,298
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	77,000	2,548
Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	20,000
Commercial Real Estate [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans		1
Home Equity Lines Of Credit [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	106,037	82,508
Home Equity Lines Of Credit [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	106,037	82,479
Home Equity Lines Of Credit [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans		29
Construction And Land [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	564,581	511,084
Construction And Land [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	564,581	476,844
Construction And Land [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans		14,240
Construction And Land [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans		20,000
Other [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	47,624	32,111
Other [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	47,622	$ 32,111
Other [Member] | Doubtful [Member]
Financing Receivable Recorded Investment [Line Items]
Gross bank loans	$ 2