Securities Owned and Sold, Not Yet Purchased (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Securities owned and sold, not yet purchased
Securities owned, at fair value	$ 5,277,000	$ 25,789,000
Securities sold, not yet purchased, at fair value	438,000	19,362,000
After-Tax Unrealized Holding Gain/(Loss)
Positions with net gains		86,000
Total gain/(loss)		86,000
Gross proceeds from the sale of available-for-sale securities	2,100,000
Pre-tax gain on the sale of available-for-sale securities	500,000
Corporate stocks-trading securities
Securities owned and sold, not yet purchased
Securities owned, at fair value	689,000	19,051,000
Securities sold, not yet purchased, at fair value	438,000	19,362,000
Corporate stocks-available-for-sale
Securities owned and sold, not yet purchased
Securities owned, at fair value		1,662,000
Mutual funds
Securities owned and sold, not yet purchased
Securities owned, at fair value	$ 4,588,000	$ 5,076,000