Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Capital Expenditures	$ 14,266	$ 14,778	$ 42,006	$ 61,753
Depreciation	8,408	7,945	25,141	23,058
Amortization	14,674	13,200	43,749	39,417
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	13,847	14,504	41,009	59,684
Depreciation	8,238	7,690	24,291	22,290
Amortization	14,603	13,143	43,495	39,245
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	6,173	7,652	20,596	24,211
Depreciation	4,980	4,222	13,290	12,069
Amortization	8,526	7,505	25,735	22,390
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	2,896	3,234	8,784	12,427
Depreciation	499	1,255	3,205	3,578
Amortization	3,014	2,683	8,550	7,999
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	720	698	2,115	3,085
Depreciation	271	298	982	901
Amortization	427	426	1,280	1,280
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	3,722	2,776	8,726	19,067
Depreciation	2,428	1,818	6,508	5,499
Amortization	2,451	2,343	7,375	7,020
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	336	144	788	894
Depreciation	60	97	306	243
Amortization	185	186	555	556
Corporate
Segment Reporting Information [Line Items]
Capital Expenditures	419	274	997	2,069
Depreciation	170	255	850	768
Amortization	$ 71	$ 57	$ 254	$ 172

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 amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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