Bank Loans (Activity In The Allowance For Loan Losses By Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 29,787	$ 20,731
Provision	4,259	1,846
Charge-offs		(47)
Recoveries	4	38
Ending Balance	34,050	22,568
Commercial And Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	24,748	16,609
Provision	2,952	1,495
Ending Balance	27,700	18,104
Securities Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,607	1,099
Provision	(2)	189
Ending Balance	1,605	1,288
Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	105	156
Provision	(21)	(51)
Ending Balance	84	105
Residential Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,241	787
Provision	88	114
Charge-offs		(47)
Recoveries	1	3
Ending Balance	1,330	857
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	264	232
Provision	1,022	38
Recoveries	3	35
Ending Balance	1,289	305
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	290	267
Provision	(23)	2
Ending Balance	267	269
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	78
Provision	40
Ending Balance	118
Qualitative [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,454	1,581
Provision	203	59
Ending Balance	$ 1,657	$ 1,640