Bank Loans (Activity In The Allowance For Loan Losses By Portfolio Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 20,731	$ 12,668	$ 8,145
Provision	9,069	8,531	8,842
Charge- offs	(144)	(531)	(4,372)
Recoveries	131	63	53
Ending Balance	29,787	20,731	12,668
Commercial And Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	16,609	9,832	5,450
Provision	8,139	7,287	8,246
Charge- offs		(510)	(3,864)
Ending Balance	24,748	16,609	9,832
Securities Based Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,099	893	638
Provision	508	211	255
Charge- offs		(5)
Ending Balance	1,607	1,099	893
Consumer [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	156		9
Provision	(58)	172	(2)
Charge- offs		(16)	(7)
Recoveries	7
Ending Balance	105	156
Residential Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	787	408	408
Provision	544	373	474
Charge- offs	(144)		(501)
Recoveries	54	6	27
Ending Balance	1,241	787	408
Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	232	198	691
Provision	(30)	(23)	(512)
Recoveries	62	57	19
Ending Balance	264	232	198
Home Equity Lines Of Credit [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	267	174	195
Provision	15	93	(21)
Recoveries	8
Ending Balance	290	267	174
Construction And Land [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance		12	13
Provision	78	(12)	(8)
Recoveries			7
Ending Balance	78		12
Qualitative [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	1,581	1,151	741
Provision	(127)	430	410
Ending Balance	$ 1,454	$ 1,581	$ 1,151