Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income (loss)	$ 27,625	$ 4,267
Adjustments to reconcile net income (loss) to net cash provided by / (used in) operating activities:
Depreciation and amortization	4,762	5,162
Amortization of Debt Discount	1,759	0
Share-based compensation	10,477	9,493
Deferred rent obligations	(977)	(1,485)
Net loss on disposal of fixed assets	218	350
Purchases of securities owned, at fair value	(2,118,048)	(3,919,095)
Proceeds from sales of securities owned, at fair value	1,864,592	4,084,293
Proceeds from sales of securities sold, not yet purchased, at fair value	802,640	1,685,014
Payments to cover securities sold, not yet purchased, at fair value	(713,115)	(1,670,358)
Net (gains) losses on securities, derivatives and other investments	(36,627)	(16,618)
Consolidated Funds
Purchases of securities owned, at fair value	0	(223,860)
Proceeds from sales of securities owned, at fair value	0	206,052
Proceeds from sales of securities sold, not yet purchased, at fair value	0	33,334
Payments to cover securities sold, not yet purchased, at fair value	0	36,462
Purchases of other investments	(19,535)	(973)
Proceeds from sales of other investments	17,116	21,270
Net realized and unrealized (gains) losses on investments and other transactions	(8,665)	(7,030)
(Increase) decrease in operating assets:
Cash acquired upon transaction	0	10,747
Cash collateral pledged	2,178	151
Securities owned, at fair value, held at broker dealer	6,033	11,212
Receivable on derivative contracts, at fair value	742	814
Securities borrowed	(1,324,748)	(173,581)
Receivable from brokers	(54,893)	46,695
Fees receivable, net of allowance	(1,563)	(7,471)
Due from related parties	(2,908)	(3,002)
Other assets	(525)	839
Consolidated Funds
Cash and cash equivalents	1,711	2,816
Other assets	4,930	(258)
Increase (decrease) in operating liabilities:
Securities sold, not yet purchased, at fair value, held at broker dealer	9,944	(38,407)
Payable for derivative contracts, at fair value	9,968	3,802
Securities loaned	1,331,985	171,202
Payable to brokers	109,854	(46,476)
Compensation payable	(17,609)	(47,604)
Fees payable	2,685	(1,788)
Due to related parties	(5)	(135)
Accounts payable, accrued expenses and other liabilities	2,752	(7,757)
Consolidated Funds
Payables to Brokers	0	10,231
Accounts payable, accrued expenses and other liabilities	(487)	(254)
Net cash provided by / (used in) operating activities	(87,734)	105,130
Cash flows from investing activities:
Purchases of other investments	(61,974)	(12,255)
Cash convertible note hedge transaction	(35,710)	0
Proceeds from sales of other investments	65,093	23,502
Tenant Allowance	1,240	0
Purchase of fixed assets	(5,857)	(554)
Net cash provided by / (used in) investing activities	(37,208)	10,693
Cash flows from financing activities:
Securities sold under agreement to repurchase	(3,657)	(159,634)
Proceeds from issuance of convertible debt	149,500	0
Deferred debt issuance cost	(3,720)	0
Proceeds from sale of warrant	15,218	0
Borrowings on short-term borrowings and other debt	6,217	2,044
Repayments on short-term borrowings and other debt	(2,023)	(1,800)
Proceeds from stock options exercised	116	0
Purchase of treasury stock	(11,298)	(235)
Cash paid to acquire net assets (contingent liability payable)	(154)	(73)
Capital contributions by non-controlling interests in operating entities	605	501
Capital withdrawals to non-controlling interests in operating entities	(3,931)	(807)
Consolidated Funds
Capital contributions by non-controlling interests in Consolidated Funds	9,535	9,680
Capital withdrawals to non-controlling interests in Consolidated Funds	(11,174)	(12,156)
Net cash provided by / (used in) financing activities	145,234	(162,480)
Change in cash and cash equivalents	20,292	(46,657)
Cash and cash equivalents at beginning of period	54,720	83,538
Cash and cash equivalents at end of period	75,012	36,881
Supplemental information
Non compete agreements and covenants with limiting conditions acquired (see Note 2)	0	460
Common stock issuance upon close of acquisition (see Note 2)	0	6,297
Purchase of treasury stock, at cost, through net settlement (see Note 21)	5,350	2,808
Discount on debt	$ 35,710	$ 0