Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Capital Expenditures	$ 27,120	$ 17,254
Depreciation	7,473	7,331
Amortization	13,077	12,679
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	26,123	16,869
Depreciation	7,217	6,995
Amortization	13,020	12,621
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	9,925	8,461
Depreciation	3,882	3,549
Amortization	7,421	7,141
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	5,390	3,947
Depreciation	1,151	1,179
Amortization	2,652	2,523
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	1,358	871
Depreciation	302	405
Amortization	427	433
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	9,032	3,349
Depreciation	1,812	1,771
Amortization	2,335	2,339
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	418	241
Depreciation	70	91
Amortization	185	185
Corporate
Segment Reporting Information [Line Items]
Capital Expenditures	997	385
Depreciation	256	336
Amortization	$ 57	$ 58

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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