CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated net income	$ 109,277	$ 161,712	$ 191,898
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Gain on originated mortgage servicing rights	(193,913)	(103,160)	(95,284)
Depreciation and amortization	141,193	131,144	97,733
Nasdaq earn-out recognition	(121,906)	(98,580)	(85,135)
Provision for credit losses on the financial guarantee liability	11,632	0	0
Provision for doubtful accounts	4,668	1,817	3,530
Equity-based compensation and allocation of net income to limited partnership units and FPUs	130,759	258,836	224,644
Employee loan amortization	73,596	38,987	27,743
Deferred tax (benefit) provision	419	(27,852)	16,387
Non-cash changes in acquisition related earnouts	(9,916)	728	374
Unrealized (gains) on loans held for sale	(24,295)	(5,174)	(18,430)
Loss (income) from an equity method investment	11,562	(7,250)	(2,750)
Realized loss (gains) on marketable securities	2,204	(4,056)	(3,256)
Realized loss (gains) on non-marketable investments	84,186	(12,159)	(17,899)
Unrealized loss (gains) on marketable securities	(5,004)	(11,303)	1,193
Change in valuation of derivative asset	13,680	51,117	(19,002)
Loan originations—loans held for sale	(12,374,231)	(8,783,225)	(8,612,671)
Loan sales—loans held for sale	11,527,010	9,563,973	8,002,872
Other	3,405	4,260	1,586
Consolidated net (loss) income, adjusted for non-cash and non-operating items	(615,674)	1,159,815	(286,467)
Changes in operating assets and liabilities:
Receivables, net	123,743	(52,021)	(129,490)
Loans, forgivable loans and other receivables from employees and partners	(127,917)	(161,897)	(109,569)
Right of use asset	11,192	(19,481)	0
Other assets	21,764	(93,823)	(9,924)
Accrued compensation	(75,369)	39,959	50,198
Right of use liability	(7,029)	72,947	0
Accounts payable, accrued expenses and other liabilities	(82,415)	17,829	152,885
Payable to subsidiaries	(25,989)	23,433	0
Net cash (used in) provided by operating activities	(777,694)	986,761	(332,367)
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired	(5,850)	(33,939)	(34,513)
Distributions from equity method investment	90	8,560	0
Proceeds from the sale of marketable securities	34,738	32,606	95,878
Purchase of non-marketable investments	0	(28,000)	(29,500)
Purchase of debt securities	(12,754)	0	0
Purchases of fixed assets	(19,626)	(34,526)	(21,016)
Purchase of mortgage servicing rights	(200)	(1,489)	(3,107)
Net cash (used in) provided by investing activities	(3,602)	(56,788)	7,742
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from warehouse facilities	12,374,231	8,783,225	8,612,671
Principal payments on warehouse facilities	(11,522,677)	(9,545,964)	(8,000,725)
Proceeds from BGC's purchase of exchangeable limited partnership units in Newmark Holdings	0	0	241,960
Proceeds from issuance of EPUs	0	0	262,169
Payments to related parties	0	0	(858,428)
Borrowings from related parties	0	0	372,950
Settlement of pre-Spin-Off related party receivables	0	33,892	0
Proceeds from the IPO, net of underwriting discounts	0	0	(8,870)
Borrowing of debt	365,000	155,000	537,575
Repayment of debt	(275,000)	(105,000)	(670,710)
Capital contribution	0	0	9,189
Securities loaned	(3,457)	36,735	(57,623)
Treasury stock repurchases	(6,364)	(37,368)	(486)
Earnings distributions to limited partnership interests and noncontrolling interests	(81,879)	(140,576)	(46,490)
Dividends to stockholders	(23,171)	(69,245)	(41,787)
Payments on acquisition earn-outs	(4,793)	(4,837)	(4,476)
Prepayment penalty on debt	0	0	(6,954)
Payment of deferred financing costs	(4,067)	(1,368)	(1,308)
Net cash provided by (used in) financing activities	817,823	(895,506)	338,657
Net increase in cash and cash equivalents and restricted cash	36,527	34,466	14,032
Cash and cash equivalents and restricted cash at beginning of period	221,872	187,406	173,374
Cash and cash equivalents and restricted cash at end of period	258,399	221,872	187,406
Cash paid during the period for:
Interest	40,640	36,959	81,838
Taxes	80,288	95,089	1,165
Supplemental disclosure of non-cash operating, investing and financing activities:
Right-of-use assets and liabilities	37,808	182,180	0
Treasury stock repurchase	$ 453	$ 4,732	$ 0