Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (303,906)	$ (33,339)	$ (432,206)	$ (89,136)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization expense			4,268	3,046
Stock-based compensation			8,521	7,066
Vesting of restricted stock awards for employee bonus			14,620	0
Loss on disposal of property and equipment			62,987	0
Change in fair value measurement of liabilities	22,747	(1,394)	60,394	(10,056)
Loss on cancellation of lease			0	206
(Gain)/loss on foreign exchange			(1,823)	3,234
Gain on write-off of accounts payable and loss on write-off of vendor deposits, net			(4,191)	0
Non-cash interest expense			36,478	47,920
Loss/(gain) on settlement of related party notes payable, notes payable and vendor payables in trust, net	94,727	(609)	96,036	(295)
Gain on forgiveness of vendor payables in trust			(1,731)	0
Reserve for unrecoverable value added taxes			6,404	0
Changes in operating assets and liabilities
Deposits			(35,796)	(7,075)
Other current assets			(15,260)	1,984
Other non-current assets			(3,186)	(45)
Accounts payable			(40,434)	11,713
Accrued expenses and other current liabilities			5,874	4,041
Transfers between vendor payables in trust and accounts payable			1,167	(134)
Net cash used in operating activities			(237,878)	(27,531)
Cash flows from investing activities
Proceeds from payments of notes receivables			0	3,600
Payments for property and equipment			(37,264)	(589)
Net cash (used in) provided by investing activities			(37,264)	3,011
Cash flows from financing activities
Proceeds from issuance of Class A Common Stock in the Business Combination			229,583	0
Proceeds from issuance of Class A Common Stock pursuant to the PIPE Financing			761,400	0
Transaction costs paid in connection with the Business Combination			(23,148)	0
Transaction costs paid in connection with the PIPE Financing			(61,130)	0
Proceeds from related party notes payable			200	10,132
Proceeds from notes payable, net of original issuance discount			172,031	25,621
Payments of related party notes payable			(38,217)	(1,000)
Payments of notes payable, including liquidation premium			(48,210)	0
Payments of notes payable issuance costs			(3,355)	(2,554)
Payments of vendor payables in trust			(27,722)	(2,231)
Payments of capital lease obligations			(2,691)	(1,806)
Transfers between vendor payables in trust and accounts payable			(1,167)	134
Proceeds from exercise of stock options			10,492	31
Payments of stock issuance costs			(1,071)	0
Net cash provided by financing activities			966,995	28,327
Effect of exchange rate changes on cash and cash equivalents and restricted cash			(2,536)	(784)
Net increase in cash and cash equivalents and restricted cash			689,317	3,023
Cash and cash equivalents and restricted cash, beginning of period			1,827	3,354	$ 3,354
Cash and cash equivalents and restricted cash, end of period	691,144	6,377	691,144	6,377	1,827
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	666,061	5,664	666,061	5,664	1,124	$ 2,221
Restricted cash	25,083	713	25,083	713	703	1,133
Total cash, cash equivalents and restricted cash, end of period	$ 691,144	$ 6,377	691,144	6,377	$ 1,827	$ 3,354
Supplemental disclosure of noncash investing and financing activities
Conversion of related party notes payable and related party accrued interest into Class A Common Stock			294,796	0
Conversion of notes payable and accrued interest into Class A Common Stock			98,375	0
Issuance of warrants			17,596	490
Conversion of assumed convertible and promissory notes payable into Class A Common Stock and Private Warrants			1,080	0
Conversion of The9 Conditional Obligation into Class A Common Stock			2,863	0
Acquisitions of property and equipment included in accounts payable			270	491
Conversion of related party customer deposit to related party notes payable			0	11,635
Supplemental disclosure of noncash investing and financing activities related to the Business Combination
Settlement of notes payable and accrued interest for a commitment to issue Class A Common Stock			68,541	0
Settlement of related party notes payable and related party accrued interest for a commitment to issue Class A Common Stock			69,218	0
Settlement of vendor payables in trust for a commitment to issue Class A Common Stock			96,186	0
Settlement of accounts payable for a commitment to issue Class A Common Stock			2,879	0
Supplemental disclosure of cash flow information
Cash paid for interest			5,837	63
Class A Common Stock
Supplemental disclosure of noncash investing and financing activities related to the Business Combination
Conversion of shares			859,182	0
Class B Common Stock
Supplemental disclosure of noncash investing and financing activities related to the Business Combination
Conversion of shares			697,611	0
Related Party Notes Payable, Notes Payable, and Warrant Liabilities
Adjustments to reconcile net loss to net cash used in operating activities
Change in fair value measurement of liabilities			$ 60,394	$ (10,056)