Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flow from operating activities:
Net income (loss) from consolidated operations	$ 506,239	$ 214,310	$ (411)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity-based compensation	15,882	8,157	3,209
Depreciation and amortization	11,004	2,962	2,107
Noncash lease expense	1,154	409	413
Loss on disposal of fixed asset	850	672	11
Amortization of premium of marketable securities	7,596	857	106
Provision for credit losses	8,931	1,170	189
Deferred taxes	(8,188)	(1,775)	(21)
Unrecognized tax benefits	348	377
Net loss on marketable securities	1,186	90
Equity loss in investee		488	777
(Gain) loss in equity-method investments	(3,734)	4,354
Other	(15)	8	52
Changes in operating assets and liabilities:
Accounts receivable	42,300	(178,480)	(839)
Other current and long-term assets	7,804	(21,149)	374
Accounts payable	(12,206)	22,617	(329)
Accrued liabilities and other liabilities	13,081	32,655	264
Income tax payable	(52,532)	53,295	24
Operating and finance lease liabilities	(1,123)	(389)	(409)
Net cash provided by operating activities	538,577	140,628	5,517
Cash flow from investing activities:
Purchases of fixed assets	(23,812)	(35,130)	(1,182)
Purchases of intangible assets	(32)
Proceeds from sale of fixed assets	63	8
Purchase of marketable securities	(710,490)	(324,359)	(52,077)
Purchase of redeemable preferred stock	(20,000)
Maturities of marketable securities	83,842	19,919	24,350
Proceeds from sale of marketable securities	185,749	17,095
Acquisition of businesses, net of cash acquired	(61,868)
Investment in equity-method investees		(3,971)	(137)
Net cash used in investing activities	(546,548)	(326,438)	(29,046)
Cash flow from financing activities:
Proceeds from public offerings of common stock, net of issuance costs	89,475	246,190	28,758
Proceeds from noncontrolling interest	10
Proceeds from exercise of stock options	86	104	38
Principal paid for finance lease	(7)
Common stock withholding for employee tax obligations	(4,155)	(62)	(21)
Borrowing under margin account		15,019
Net cash provided by financing activities	85,405	261,251	28,775
Repayment of notes payable	(4)
Effect of exchange rate changes on cash and cash equivalents	34	20	(17)
Net increase in cash and cash equivalents	77,468	75,461	5,229
Cash and cash equivalents at beginning of period	87,426	11,965	6,736
Cash and cash equivalents at end of period	164,894	87,426	11,965
Supplemental disclosures of cash flow information:
Income taxes paid	237,069	20,612	20
Supplemental disclosures of non-cash investing and financing activities:
Contingent consideration for business acquisition included in current liabilities	10,000
Purchases of fixed assets in accounts payable	1,075	3,402	557
Operating lease right-of-use assets obtained in exchange for lease liabilities	1,797	402	110
Operating lease right-of-use assets reduced due to lease modification or termination	399	1,853
Public offerings proceeds in other receivable included in other current assets		17,799
Finance lease right-of-use assets obtained in exchange for lease liabilities	1,693
Public offerings costs included in accounts payable	$ 5	$ 359	$ 129