CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated net income	$ 99,525	$ 122,569	$ 114,404	$ 178,039
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Gain on originated mortgage servicing rights			(126,571)	(73,873)
Depreciation and amortization	29,627	36,781	104,613	98,510
Nasdaq earn-out recognition			(121,906)	(98,580)
Provision for credit losses on the financial guarantee liability			14,702	0
Provision for doubtful accounts			2,976	1,575
Equity-based compensation and allocation of net income to limited partnership units and FPUs			74,544	109,872
Employee loan amortization			50,193	31,688
Deferred tax (benefit) provision			(20)	956
Unrealized (gains) on loans held for sale			(27,136)	(22,522)
Loss (income) from an equity method investment	7,400	(1,300)	11,562	(6,000)
Change in fair value of contingent consideration			(11,445)	639
Realized loss (gains) on marketable securities			2,204	(4,056)
Unrealized loss (gains) on non-marketable investments			26,837	(20,960)
Unrealized (gains) on marketable securities			0	(4,445)
Change in valuation of derivative asset			7,110	37,181
Loan originations—loans held for sale			(8,285,891)	(7,511,234)
Loan sales—loans held for sale			6,990,582	7,820,263
Other			3,899	3,234
Consolidated net (loss) income, adjusted for non-cash and non-operating items			(1,169,343)	540,287
Changes in operating assets and liabilities:
Receivables, net			120,729	(24,293)
Loans, forgivable loans and other receivables from employees and partners			(130,037)	(102,745)
Other assets			194	(62,883)
Accrued compensation			(98,191)	13,326
Accounts payable, accrued expenses and other liabilities			(40,031)	24,114
Payables to related parties			(24,371)	5,609
Net cash (used in) provided by operating activities			(1,341,050)	393,415
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired			(5,850)	(18,212)
Distributions from equity method investment			0	7,293
Proceeds from the sale of marketable securities			34,738	32,606
Purchase of non-marketable investments			0	(28,000)
Purchases of fixed assets			(16,182)	(23,447)
Purchase of mortgage servicing rights			(200)	(845)
Net cash provided by (used in) investing activities			12,506	(30,605)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from warehouse facilities			8,285,891	7,511,234
Principal payments on warehouse facilities			(6,985,205)	(7,802,761)
Settlement of pre-Spin-Off related party receivables			0	33,892
Borrowing of debt			365,000	155,000
Repayment of debt			(75,000)	(95,000)
Securities loaned			(36,735)	24,838
Treasury stock repurchases			0	(33,983)
Earnings distributions to limited partnership interests and noncontrolling interests			(81,879)	(112,691)
Dividends to stockholders			(21,362)	(51,659)
Payments on acquisition earn-outs			(3,981)	(3,407)
Payment of deferred financing costs			(3,395)	(1,363)
Net cash provided by (used in) financing activities			1,443,334	(375,900)
Net (decrease) increase in cash and cash equivalents and restricted cash			114,790	(13,090)
Cash and cash equivalents and restricted cash at beginning of period			221,872	187,406	$ 187,406
Cash and cash equivalents and restricted cash at end of period	$ 336,662	$ 174,316	336,662	174,316	$ 221,872
Cash paid during the period for:
Interest			22,435	19,392
Taxes			69,460	82,939
Supplemental disclosure of non-cash operating, investing and financing activities:
Right-of-use assets and liabilities			$ 26,444	$ 52,381