Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Capital expenditure	$ 23,516	$ 14,266	$ 57,146	$ 42,006
Depreciation	8,558	8,408	24,942	25,141
Amortization	10,382	14,674	43,777	43,749
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditure	23,030	13,847	55,770	41,009
Depreciation	8,380	8,238	24,402	24,291
Amortization	10,325	14,603	43,579	43,495
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital expenditure	8,404	6,173	24,167	20,596
Depreciation	5,050	4,980	15,710	13,290
Amortization	4,515	8,526	21,315	25,735
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital expenditure	3,476	2,896	9,926	8,784
Depreciation	513	499	1,438	3,205
Amortization	1,736	3,014	8,127	8,550
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital expenditure	1,080	720	3,057	2,115
Depreciation	283	271	857	982
Amortization	1,808	427	6,348	1,280
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital expenditure	9,843	3,722	17,980	8,726
Depreciation	2,498	2,428	6,273	6,508
Amortization	2,121	2,451	7,274	7,375
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital expenditure	227	336	640	788
Depreciation	36	60	124	306
Amortization	145	185	515	555
Corporate
Segment Reporting Information [Line Items]
Capital expenditure	486	419	1,376	997
Depreciation	178	170	540	850
Amortization	$ 57	$ 71	$ 198	$ 254

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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