Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Capital expenditure	$ 19,349	$ 19,621
Depreciation	8,389	8,531
Amortization	10,386	9,424
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditure	18,807	19,006
Depreciation	7,440	8,327
Amortization	10,307	9,360
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital expenditure	6,432	9,071
Depreciation	2,904	5,354
Amortization	5,111	4,646
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital expenditure	3,165	4,339
Depreciation	2,181	468
Amortization	2,122	1,818
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital expenditure	1,119	648
Depreciation	604	282
Amortization	1,892	1,824
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital expenditure	7,675	4,566
Depreciation	1,579	1,992
Amortization	0	177
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital expenditure	416	382
Depreciation	172	231
Amortization	1,182	895
Corporate overhead
Segment Reporting Information [Line Items]
Capital expenditure	542	615
Depreciation	949	204
Amortization	$ 79	$ 64

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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Future cash outflow to pay for purchases of fixed assets that have occurred.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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