Bank Loans (Activity In The Allowance For Loan Losses By Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 34,050	$ 22,567	$ 29,787	$ 20,731
Provision	1,824	1,416	6,082	3,262
Charge-offs	(13)	(69)	(13)	(116)
Recoveries	5	9	10	46
Ending Balance	35,866	23,923	35,866	23,923
Commercial And Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	27,700	18,104	24,748	16,609
Provision	2,116	1,193	5,068	2,688
Ending Balance	29,816	19,297	29,816	19,297
Securities Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,605	1,288	1,607	1,099
Provision	126	157	124	346
Ending Balance	1,731	1,445	1,731	1,445
Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	84	104	105	156
Provision	23	19	2	(33)
Ending Balance	107	123	107	123
Residential Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,330	857	1,241	787
Provision	210	114	298	229
Charge-offs	(13)	(69)	(13)	(116)
Recoveries	2	2	3	4
Ending Balance	1,529	904	1,529	904
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,289	305	264	232
Provision	(780)	(26)	241	12
Recoveries	3	7	7	42
Ending Balance	512	286	512	286
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	267	269	290	267
Provision	16	(4)	(7)	(2)
Ending Balance	283	265	283	265
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	118		78
Provision	26		66
Ending Balance	144		144
Qualitative [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,657	1,640	1,454	1,581
Provision	87	(37)	290	22
Ending Balance	$ 1,744	$ 1,603	$ 1,744	$ 1,603