Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Securities owned, at fair value:	$ 21,943	$ 7,436
Liabilities
Securities sold, not yet purchased, at fair value:	22,856	2,953
Recurring basis | Total
Assets
Total Assets	25,482	10,164
Liabilities
Total Liabilities	22,856	2,953
Recurring basis | Total | Tax free money market mutual funds
Assets
Cash and cash equivalents:	33	33
Recurring basis | Total | Money market mutual funds
Assets
Cash and cash equivalents:	3,506	2,695
Recurring basis | Total | Corporate stocks-trading securities
Assets
Securities owned, at fair value:	17,867	2,894
Liabilities
Securities sold, not yet purchased, at fair value:	22,856	2,953
Recurring basis | Total | Mutual funds
Assets
Securities owned, at fair value:	4,076	4,542
Recurring basis | Level 1
Assets
Total Assets	25,482	10,164
Liabilities
Total Liabilities	22,856	2,953
Recurring basis | Level 1 | Tax free money market mutual funds
Assets
Cash and cash equivalents:	33	33
Recurring basis | Level 1 | Money market mutual funds
Assets
Cash and cash equivalents:	3,506	2,695
Recurring basis | Level 1 | Corporate stocks-trading securities
Assets
Securities owned, at fair value:	17,867	2,894
Liabilities
Securities sold, not yet purchased, at fair value:	22,856	2,953
Recurring basis | Level 1 | Mutual funds
Assets
Securities owned, at fair value:	$ 4,076	$ 4,542