Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 193,066	$ 130,052
Cash collateral pledged	16,092	17,888
Segregated cash	154,191	116,268
Securities owned, at fair value	644,169	673,221
Receivable on derivative contracts, at fair value	32,229	69,177
Securities Borrowed, Gross	713,288	443,148
Securities borrowed	713,288	443,148
Other investments	167,428	141,548
Deposits with clearing organizations, brokers and banks	98,646	93,996
Receivable from brokers, dealers and clearing organizations	644,392	508,178
Receivable from customers, net of allowance of $551 and $1,550, respectively	33,240	49,891
Fees receivable, net of allowance of $2,040 and $1,736, respectively	111,756	111,784
Due from related parties	32,509	34,814
Fixed assets, net of accumulated depreciation and amortization of $33,150 and $28,355, respectively	41,458	40,496
Goodwill	60,678	60,678
Intangible assets, net of accumulated amortization of $37,038 and $33,081, respectively	25,998	29,955
Deferred tax asset, net	101,683	116,323
Other assets	67,118	88,268
Consolidated Funds
Cash and cash equivalents, Consolidated Funds	18,747	21,988
Securities owned, at fair value	108,901	165,916
Receivable on derivative contracts, at fair value	1,911	2,520
Other Investments, Consolidated Funds	183,290	374,111
Receivable from brokers, Consolidated Funds	11,017	5,644
Other assets, Consolidated Funds	355	388
Total Assets	3,462,162	3,296,252
Liabilities
Securities sold, not yet purchased, at fair value	374,518	342,527
Payable for derivative contracts, at fair value	30,002	42,750
Securities Loaned, Gross	548,629	456,831
Securities loaned	548,629	456,831
Payables to brokers, dealers and clearing organizations	210,326	252,153
Payable to customers	470,476	352,467
Commission management payable	90,233	70,451
Compensation payable	189,249	150,206
Notes payable and other debt	271,082	173,458
Convertible debt	133,126	141,502
Fees payable	22,258	8,047
Due to related parties	571	570
Accounts payable, accrued expenses and other liabilities	94,731	96,533
Consolidated Funds
Payable for derivative contracts, at fair value	2,189	7,130
Payable to brokers	1,936	751
Capital withdrawals payable	11,120	11,931
Accounts payable, accrued expenses and other liabilities	260	322
Total Liabilities	2,450,706	2,107,629
Commitments and Contingencies
Redeemable non-controlling interests	203,212	440,604
Stockholders' equity
Additional paid-in capital	1,061,274	1,004,664
(Accumulated deficit) retained earnings	(38,029)	(70,116)
Accumulated other comprehensive income (loss)	(3)	(8)
Less: Class A common stock held in treasury, at cost, 14,092,732 and 12,133,276 shares as of September 30, 2018 and December 31, 2017, respectively.	(215,323)	(186,846)
Total Stockholders' Equity	808,244	748,019
Total Liabilities and Stockholders' Equity	3,462,162	3,296,252
Convertible Preferred Stock
Stockholders' equity
Preferred stock	1	1
Common Stock Class A
Stockholders' equity
Common stock	324	324
Less: Class A common stock held in treasury, at cost, 14,092,732 and 12,133,276 shares as of September 30, 2018 and December 31, 2017, respectively.	(215,323)	(186,846)
Common Stock Class B
Stockholders' equity
Common stock	$ 0	$ 0