Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Capital Expenditures	$ 72,834	$ 52,536	$ 78,567
Depreciation	33,657	33,481	30,959
Amortization	54,280	59,152	52,975
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	71,120	51,385	75,727
Depreciation	32,944	32,463	29,918
Amortization	54,017	58,828	52,745
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	32,454	26,472	29,061
Depreciation	21,237	19,040	16,206
Amortization	25,886	34,159	30,240
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	13,027	11,100	15,588
Depreciation	1,933	3,646	4,821
Amortization	9,905	11,654	10,694
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	3,884	2,614	3,958
Depreciation	1,142	1,241	1,214
Amortization	8,166	2,321	1,707
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	20,968	10,275	25,909
Depreciation	8,468	8,185	7,336
Amortization	9,400	9,955	9,365
Operating Segments \| Investments in New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	787	924	1,211
Depreciation	164	351	341
Amortization	660	739	739
Corporate Overhead
Segment Reporting Information [Line Items]
Capital Expenditures	1,714	1,151	2,840
Depreciation	713	1,018	1,041
Amortization	$ 263	$ 324	$ 230

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives.

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