Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 502,024	$ 462,134
Cash segregated under regulatory requirements	6,895	3,199
Reverse repurchase agreements	54,659	0
Securities owned	35,357	32,361
Marketable securities	164,820	650,400
Receivables from broker-dealers, clearing organizations, customers and related broker-dealers	497,557	812,344
Accrued commissions receivable, net	374,734	342,299
Loans, forgivable loans and other receivables from employees and partners, net	267,527	158,194
Fixed assets, net	165,867	147,505
Investments	33,439	29,759
Goodwill	863,690	811,766
Other intangible assets, net	247,723	233,967
Receivables from related parties	6,967	9,050
Other assets	287,141	289,659
Total assets	3,508,400	3,982,637
Liabilities, Redeemable Partnership Interest, and Equity
Securities loaned	0	117,890
Accrued compensation	333,144	303,959
Payables to broker-dealers, clearing organizations, customers and related broker-dealers	375,152	714,823
Payables to related parties	28,976	22,470
Accounts payable, accrued and other liabilities	599,046	693,539
Notes payable and collateralized borrowings	965,767	840,877
Total liabilities	2,302,085	2,693,558
Commitments and contingencies (Note 20)
Redeemable partnership interest	52,577	57,145
Stockholders' equity:
Additional paid-in capital	1,466,586	1,109,000
Treasury stock, at cost: 47,679 and 36,796 shares of Class A common stock at December 31, 2016 and December 31, 2015, respectively	(288,743)	(212,331)
Retained deficit	(358,526)	(290,208)
Accumulated other comprehensive income (loss)	(23,199)	(25,056)
Total stockholders' equity	841,863	634,407
Noncontrolling interest in subsidiaries	311,875	597,527
Total equity	1,153,738	1,231,934
Total liabilities, redeemable partnership interest, and equity	3,508,400	3,982,637
Contingent Consideration Classified as Equity [Member]
Stockholders' equity:
Contingent Class A common stock	42,472	50,095
Class A Common Stock [Member]
Stockholders' equity:
Common stock value	2,925	2,559
Total equity	2,925	2,559
Class B Common Stock [Member]
Stockholders' equity:
Common stock value	348	348
Total equity	$ 348	$ 348