Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated net income (loss)	$ 38,775	$ 58,867	$ 153,488
Adjustments to reconcile consolidated net income (loss) to net cash provided by (used in) operating activities:
Gain on Insurance Business Disposition	0	0	(312,941)
Fixed asset depreciation and intangible asset amortization	80,417	75,054	81,874
Employee loan amortization and reserves on employee loans	51,313	49,533	217,655
Equity-based compensation and allocations of net income to limited partnership units and FPUs	355,378	251,071	256,164
Deferred compensation expense	54	(542)	347
Losses (gains) on equity method investments	(9,152)	(10,920)	(6,706)
Unrealized/realized losses (gains) on financial instruments owned, at fair value and other investments	(4,406)	1,208	17
Amortization of discount (premium) on notes payable	3,662	2,801	3,592
Impairment of fixed assets, intangible assets and investments	3,144	6,139	11,246
Deferred tax provision (benefit)	(60,556)	(14,628)	(11,947)
Change in estimated acquisition earn-out payables	1,442	1,034	4,285
Forfeitures of Class A common stock	(1,190)	(263)	(553)
Loss (gain) on divestiture	0	1,029	0
Other	0	(1,914)	(4,915)
Consolidated net income (loss), adjusted for non-cash and non-operating items	458,881	418,469	391,606
Decrease (increase) in operating assets:
Financial instruments owned, at fair value	(5,475)	2,383	17,626
Receivables from broker-dealers, clearing organizations, customers and related broker-dealers	212,490	222,567	(482,669)
Accrued commissions receivable, net	(5,750)	6,287	(101,314)
Loans, forgivable loans and other receivables from employees and partners, net	(77,464)	(61,205)	(38,571)
Receivables from related parties	(1,380)	3,621	8,377
Other assets	19,803	(8,469)	1,543
Increase (decrease) in operating liabilities:
Accrued compensation	18,450	(25,178)	17,989
Payables to broker-dealers, clearing organizations, customers and related broker-dealers	(203,902)	(252,490)	477,083
Payables to related parties	24,145	(43,782)	18,596
Accounts payable, accrued and other liabilities	(34,595)	(37,841)	106,919
Net cash provided by (used in) operating activities	405,203	224,362	417,185
CASH FLOWS FROM INVESTING ACTIVITIES:
Gross proceeds from Insurance Business Disposition	0	0	534,916
Cash and restricted cash transferred as part of Insurance Business Disposition	0	0	(369,407)
Proceeds from disposal of subsidiary	0	512	0
Purchases of fixed assets	(14,924)	(10,591)	(10,112)
Capitalization of software development costs	(44,974)	(48,169)	(43,178)
Purchase of equity method investments	0	(588)	(1,115)
Proceeds from equity method investments	9,421	6,118	10,029
Payments for acquisitions, net of cash acquired	(39,755)	0	0
Purchase of other assets	(475)	(612)	0
Net cash provided by (used in) investing activities	(90,707)	(53,330)	121,133
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayments of long-term debt and collateralized borrowings	(623,251)	(6,391)	(566,244)
Issuance of long-term debt and collateralized borrowings, net of deferred issuance costs	754,321	(75)	298,419
Earnings distributions to limited partnership interests and other noncontrolling interests	(19,041)	(28,877)	(52,169)
Redemption and repurchase of equity awards	(117,867)	(76,219)	(110,565)
Dividends to stockholders	(17,381)	(14,859)	(15,098)
Repurchase of Class A common stock	(114,580)	(103,888)	(365,398)
Proceeds from sale of Cantor units in BGC Holdings	11,539	1,487	7,894
Pre-acquisition cash capital contribution to Futures Exchange Group	0	0	3,845
Acquisition of Futures Exchange Group	0	0	(9,022)
Short term borrowings, net of repayments	(1,917)	0	0
Payments on acquisition earn-outs	(18,703)	(4,384)	(11,199)
Net cash provided by (used in) financing activities	(146,880)	(233,206)	(819,537)
Effect of exchange rate changes on Cash and cash equivalents, and Cash segregated under regulatory requirements	3,270	(2,615)	(5,388)
Net increase (decrease) in cash and cash equivalents	170,886	(64,789)	(286,607)
Cash and cash equivalents, and Cash segregated under regulatory requirements at beginning of period	502,010	566,799	853,406
Cash and cash equivalents, and Cash segregated under regulatory requirements at end of period	672,896	502,010	566,799
Supplemental cash information:
Cash paid during the period for taxes	70,718	35,782	43,357
Cash paid during the period for interest	80,664	53,655	66,450
Supplemental non-cash information:
Issuance of Class A common stock upon exchange of limited partnership interests	45,868	34,889	157,547
Issuance Of Class Common Stock And Limited Partnership Interests For Acquisitions	7,275	2,710	1,160
ROU assets and liabilities	$ 27,201	$ 44,123	$ 7,367