Bank Loans (Aging Of The Recorded Investment In Past Due Loans) (Details) - USD ($)		Mar. 31, 2022		Dec. 31, 2021
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 17,569,000		$ 23,432,000
Total		17,761,548,000		16,743,487,000
Non-Accrual		16,838,000	[1]	17,193,000	[2]
Restructured		154,000	[1]	154,000	[2]
Nonperforming loans with no allowance		0	[1]	1,000	[2]
Total		16,992,000	[1]	17,348,000	[2]
Loans past due 90 days and still accruing interest		0		0
Non-Accrual		16,838,000	[1]	17,193,000	[2]
30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		720,000		15,528,000
90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		16,849,000		7,904,000
Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		17,743,979,000		16,720,055,000
Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,030,000		7,526,000
Total		6,008,507,000		5,482,026,000
Non-Accrual		1,332,000		1,332,000	[2]
Restructured		154,000		154,000	[2]
Nonperforming loans with no allowance	[2]			0
Total		1,486,000	[1]	1,486,000	[2]
Non-Accrual		1,332,000		1,332,000	[2]
Residential Mortgage | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		698,000		6,194,000
Residential Mortgage | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		1,332,000		1,332,000
Residential Mortgage | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		6,006,477,000		5,474,500,000
Commercial And Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		15,477,000		15,861,000
Total		7,656,507,000		7,345,753,000
Non-Accrual		15,477,000		15,861,000	[2]
Total		15,477,000	[1]	15,861,000	[2]
Non-Accrual		15,477,000		15,861,000	[2]
Commercial And Industrial | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				9,290,000
Commercial And Industrial | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		15,477,000		6,571,000
Commercial And Industrial | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		7,641,030,000		7,329,892,000
Securities-Based Loans [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		2,954,212,000		2,880,158,000
Securities-Based Loans [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		2,954,212,000		2,880,158,000
Commercial Real Estate [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				1,000
Total		499,825,000		409,847,000
Nonperforming loans with no allowance	[2]			1,000
Total	[2]			1,000
Commercial Real Estate [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				1,000
Commercial Real Estate [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		499,825,000		409,846,000
Home Equity Lines Of Credit [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		29,000		0
Total		87,901,000		82,508,000
Non-Accrual		29,000
Total	[1]	29,000
Non-Accrual		29,000
Home Equity Lines Of Credit [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due				0
Home Equity Lines Of Credit [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		29,000
Home Equity Lines Of Credit [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		87,872,000		82,508,000
Construction And Land [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total		521,623,000		511,084,000
Construction And Land [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		521,623,000		511,084,000
Other [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		33,000		44,000
Total		32,973,000		32,111,000
Other [Member] | 30 - 89 Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		22,000		44,000
Other [Member] | 90 or More Days Past Due [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		11,000
Other [Member] | Current Balance [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		$ 32,940,000		$ 32,067,000

[1] There were no loans past due 90 days and still accruing interest at March 31, 2022

[2] There were no loans past due 90 days and still accruing interest at December 31, 2021.