Bank Loans (Activity In The Allowance For Loan Losses By Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 99,196	$ 115,821	$ 112,029	$ 95,579
CECL Adoption				(11,736)
Provision	(4,903)	(1,777)	(12,534)	30,369
Charge-offs		(23)	(5,202)	(193)
Recoveries		92		94
Ending Balance	94,293	114,113	94,293	114,113
Commercial And Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	46,943	65,503	67,222	69,949
CECL Adoption				(19,940)
Provision	(256)	10,303	(15,333)	25,949
Charge-offs		(1)	(5,202)	(153)
Recoveries		4		4
Ending Balance	46,687	75,809	46,687	75,809
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	21,267	24,043	16,300	14,253
CECL Adoption				3,499
Provision	2,637	(6,360)	7,604	(69)
Ending Balance	23,904	17,683	23,904	17,683
Securities-Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	2,519	1,807	2,015	2,361
CECL Adoption				1,346
Provision	808	95	1,312	(1,805)
Ending Balance	3,327	1,902	3,327	1,902
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	11,903	10,647	8,580	3,564
CECL Adoption				791
Provision	(6,582)	(2,730)	(3,259)	3,562
Ending Balance	5,321	7,917	5,321	7,917
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	15,953	13,075	17,275	4,613
CECL Adoption				2,674
Provision	(1,620)	(2,889)	(2,942)	2,899
Ending Balance	14,333	10,186	14,333	10,186
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	426	499	374	442
CECL Adoption				39
Provision	48	(205)	100	(188)
Recoveries		87		88
Ending Balance	474	381	474	381
Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	185	247	263	397
CECL Adoption				(145)
Provision	62	9	(16)	21
Charge-offs		(22)		(40)
Recoveries		1		2
Ending Balance	$ 247	$ 235	$ 247	$ 235

Loans and leases receivable allowance impact of current expected credit loss adoption.

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- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

+ References

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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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.

+ References

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Amount of expense related to estimated loss from loan and lease transactions.

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