Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Capital Expenditures	$ 26,431	$ 15,721	$ 58,227	$ 52,615
Depreciation	6,108	5,579	17,946	16,494
Amortization	10,837	9,813	31,806	28,611
Private Banks [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	12,707	7,797	31,317	26,105
Depreciation	3,141	2,922	9,214	10,211
Amortization	7,604	6,342	22,300	18,485
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	4,899	3,731	11,060	11,381
Depreciation	864	759	2,527	1,762
Amortization	2,512	2,341	7,371	6,825
Institutional Investors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	1,955	239	3,970	3,169
Depreciation	302	295	903	714
Amortization	383	363	1,133	1,058
Investment Managers [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	5,286	3,115	9,128	8,337
Depreciation	1,039	907	3,029	1,931
Amortization	255	242	755	706
Investments In New Businesses [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	379	498	662	1,694
Depreciation	572	511	1,706	1,461
Amortization	26	468	76	1,366
Total From Business Segments [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	25,226	15,380	56,137	50,686
Depreciation	5,918	5,394	17,379	16,079
Amortization	10,780	9,756	31,635	28,440
Corporate Overhead [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	1,205	341	2,090	1,929
Depreciation	190	185	567	415
Amortization	$ 57	$ 57	$ 171	$ 171