Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Capital expenditure	$ 14,848	$ 23,516	$ 49,698	$ 57,146
Depreciation	9,197	8,558	26,509	24,942
Amortization	9,797	10,382	28,851	43,777
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditure	14,541	23,030	48,414	55,770
Depreciation	8,950	8,380	25,852	24,402
Amortization	9,723	10,325	28,648	43,579
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital expenditure	7,580	8,404	24,652	24,167
Depreciation	5,565	5,050	16,369	15,710
Amortization	4,852	4,515	14,216	21,315
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital expenditure	3,545	3,476	11,499	9,926
Depreciation	540	513	1,557	1,438
Amortization	1,933	1,736	5,696	8,127
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital expenditure	390	1,080	1,495	3,057
Depreciation	338	283	923	857
Amortization	1,834	1,808	5,487	6,348
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital expenditure	2,804	9,843	10,002	17,980
Depreciation	2,424	2,498	6,789	6,273
Amortization	959	2,121	2,815	7,274
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital expenditure	222	227	766	640
Depreciation	83	36	214	124
Amortization	145	145	434	515
Corporate overhead
Segment Reporting Information [Line Items]
Capital expenditure	307	486	1,284	1,376
Depreciation	247	178	657	540
Amortization	$ 74	$ 57	$ 203	$ 198

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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