Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Capital expenditure	$ 17,758	$ 17,162	$ 33,630	$ 27,740
Depreciation	8,286	8,424	16,384	16,733
Amortization	16,508	14,723	33,395	29,075
Operating Segments
Segment Reporting Information [Line Items]
Capital expenditure	17,313	16,744	32,740	27,162
Depreciation	8,107	8,075	16,022	16,053
Amortization	16,438	14,598	33,254	28,892
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital expenditure	8,541	8,594	15,763	14,423
Depreciation	5,554	4,178	10,660	8,310
Amortization	8,261	8,633	16,800	17,209
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital expenditure	3,423	3,580	6,450	5,888
Depreciation	469	1,417	925	2,706
Amortization	3,158	2,909	6,391	5,536
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital expenditure	1,028	884	1,977	1,395
Depreciation	285	353	574	711
Amortization	2,257	427	4,540	853
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital expenditure	4,113	3,373	8,137	5,004
Depreciation	1,755	2,027	3,775	4,080
Amortization	2,577	2,444	5,153	4,924
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital expenditure	208	313	413	452
Depreciation	44	100	88	246
Amortization	185	185	370	370
Corporate
Segment Reporting Information [Line Items]
Capital expenditure	445	418	890	578
Depreciation	179	349	362	680
Amortization	$ 70	$ 125	$ 141	$ 183

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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