Bank Loans (Schedule Of Balance And Associated Percentage Of Each Major Loan Category In Bank Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 20,899,444	$ 20,602,558
Loans in process	(51,795)	(3,526)
Unamortized loan fees, net	(20,719)	(22,287)
Allowance for loan losses	(117,162)	(111,653)	$ (104,198)	$ (99,344)
Loans held for investment, net	$ 20,709,768	$ 20,465,092
Gross bank loans, Percent	100.00%	100.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 7,494,788	$ 7,371,671
Allowance for loan losses	$ (22,696)	$ (20,441)	(32,927)	(28,560)
Gross bank loans, Percent	35.90%	35.80%
Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 4,755,664	$ 4,897,176
Allowance for loan losses	$ (55,734)	$ (54,143)	(46,188)	(44,661)
Gross bank loans, Percent	22.80%	23.80%
Fund Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 4,623,423	$ 4,182,641
Allowance for loan losses	$ (12,943)	$ (11,711)	(8,392)	(8,868)
Gross bank loans, Percent	22.10%	20.30%
Securities-Based Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 2,558,343	$ 2,724,551
Allowance for loan losses	$ (3,117)	$ (3,157)	(3,976)	(4,006)
Gross bank loans, Percent	12.20%	13.20%
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 663,325	$ 675,599
Allowance for loan losses	$ (11,566)	$ (12,897)	(3,680)	(3,934)
Gross bank loans, Percent	3.20%	3.30%
Construction And Land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 644,800	$ 593,191
Allowance for loan losses	$ (10,317)	$ (8,568)	(8,121)	(8,536)
Gross bank loans, Percent	3.10%	2.90%
Home Equity Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 109,197	$ 107,136
Allowance for loan losses	$ (412)	$ (364)	(683)	(511)
Gross bank loans, Percent	0.50%	0.50%
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross bank loans	$ 49,904	$ 50,593
Allowance for loan losses	$ (377)	$ (372)	$ (231)	$ (268)
Gross bank loans, Percent	0.20%	0.20%

Loans and leases payable receivable loans in process.

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Loans receivable held for investment net not part of disposal group mortgage.

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Percentage of loans and leases receivable gross carrying amount.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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