Condensed Consolidated Statements of Financial Condition (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 110,175	$ 36,354
Cash collateral pledged	9,801	8,633
Securities owned, at fair value	986,424	474,095
Securities purchased under agreements to resell	77,332	97,755
Other investments	49,042	40,320
Receivable from brokers	124,987	95,937
Fees receivable	22,442	31,688
Due from related parties (see Note 18)	19,975	16,370
Fixed assets, net of accumulated depreciation and amortization of $20,357 and $17,764, respectively	47,064	36,591
Goodwill	27,179	27,179
Intangible assets, net of accumulated amortization of $9,623 and $8,146, respectively	16,598	12,754
Other assets	33,277	19,456
Total Assets	1,793,457	1,247,170
Liabilities and Stockholders' Equity
Securities sold, not yet purchased, at fair value	442,261	197,916
Securities sold under agreements to repurchase	169,439	192,165
Payable to brokers	321,226	85,655
Compensation payable	26,731	76,204
Short-term borrowings and other debt	6,618	31,733
Fees payable (see Note 18)	6,428	8,797
Due to related parties (see Note 18)	2,557	9,187
Accounts payable, accrued expenses and other liabilities	61,718	42,267
Total Liabilities	1,041,150	653,568
Commitments and Contingencies (see Note 13)
Redeemable non-controlling interests	114,349	144,346
Stockholders' equity
Preferred stock, par value $0.01 per share; 10,000,000 shares authorized, no shares issued and outstanding
Additional paid-in capital	674,205	504,480
(Accumulated deficit) retained earnings	(35,851)	(55,970)
Accumulated other comprehensive income	375	20
Less: Class A common stock held in treasury, at cost: 499,136 shares as of June 30, 2011	(1,901)
Total Stockholders' Equity	637,958	449,256
Total Liabilities and Stockholders' Equity	1,793,457	1,247,170
Common Stock Class A
Stockholders' equity
Common stock	1,130	726
Common Stock Class B
Stockholders' equity
Common stock
Consolidated Funds
Assets
Cash and cash equivalents	789	7,210
Securities owned, at fair value	6,191	8,722
Other investments	261,898	333,374
Other assets	283	732
Liabilities and Stockholders' Equity
Capital withdrawals payable	3,510	7,817
Accounts payable, accrued expenses and other liabilities	$ 662	$ 1,827