CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION
Financial instruments owned, at fair value, financial instruments pledged (in dollars)	$ 0	$ 1,095,431
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	10,000,000	10,000,000
Common stock, issued shares	6,688,387	6,688,387
Common stock, outstanding shares	6,196,143	6,221,959
Treasury stock, shares	492,244	466,428