Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Capital Expenditures	$ 19,909	$ 17,739	$ 57,336	$ 55,023
Depreciation	7,409	7,255	22,162	21,515
Amortization	12,947	12,405	38,407	36,420
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	19,246	17,279	55,702	53,889
Depreciation	7,089	6,938	21,178	20,610
Amortization	12,890	12,347	38,236	36,247
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	8,018	7,999	25,240	27,767
Depreciation	3,640	3,427	10,774	10,069
Amortization	7,322	6,943	21,680	20,317
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	4,468	3,927	12,973	12,471
Depreciation	1,162	1,168	3,506	3,378
Amortization	2,609	2,445	7,682	7,203
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	1,070	962	2,990	2,926
Depreciation	393	410	1,212	1,310
Amortization	440	427	1,300	1,281
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	5,311	4,104	13,535	9,994
Depreciation	1,793	1,796	5,384	5,411
Amortization	2,334	2,346	7,019	7,036
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	379	287	964	731
Depreciation	101	137	302	442
Amortization	185	186	555	410
Corporate
Segment Reporting Information [Line Items]
Capital Expenditures	663	460	1,634	1,134
Depreciation	320	317	984	905
Amortization	$ 57	$ 58	$ 171	$ 173

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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