Bank Loans (Activity In The Allowance For Loan Losses By Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 99,344	$ 112,029
Provision	(4,854)	(3,427)
Charge-offs		(934)
Recoveries		0
Ending Balance	104,198	107,668
Commercial And Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	53,529	67,222
Provision	1,051	9,972
Charge-offs		(934)
Recoveries		0
Ending Balance	54,580	56,316
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	28,560	16,300
Provision	4,367	365
Ending Balance	32,927	16,665
Securities-Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	4,006	2,015
Provision	(30)	154
Ending Balance	3,976	2,169
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	3,934	8,580
Provision	(254)	(4,480)
Ending Balance	3,680	13,060
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	8,536	17,275
Provision	(415)	1,598
Ending Balance	8,121	18,873
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	511	374
Provision	172	(33)
Recoveries		0
Ending Balance	683	341
Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	268	263
Provision	(37)	19
Charge-offs		0
Recoveries		0
Ending Balance	$ 231	$ 244