Schedule I — Condensed Financial Information of Registrant - Condensed Balance Sheets (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 449,667	$ 790,151
Restricted cash, current	100,000	0
Short-term investments	330,000	16,300
Prepayments and other current assets	41,527	22,995
Total current assets	1,050,480	939,606
Total assets	1,185,753	1,036,295
Current liabilities
Other current liabilities	58,720	82,972
Total current liabilities	299,385	203,067
Total liabilities	344,855	240,177
Shareholders’ equity
Ordinary shares (par value of $0.000006 per share; 5,000,000,000 shares authorized, 1,082,614,740 and 977,151,270 shares issued as of December 31, 2024 and 2023, respectively; 1,077,702,540 and 972,239,070 shares outstanding as of December 31, 2024 and 2023)	7	6
Additional paid-in capital	3,264,295	2,975,302
Accumulated deficit	(2,453,083)	(2,195,980)
Accumulated other comprehensive income	50,515	37,626
Treasury stock	(20,836)	(20,836)
Total shareholders’ equity	840,898	796,118	$ 1,045,595	$ 1,379,956
Total liabilities and shareholders’ equity	$ 1,185,753	$ 1,036,295
Stockholders' equity, par value and number of shares
Ordinary shares, par value (in dollars per share)	$ 0.000006	$ 0.000006
Ordinary shares, shares authorized (in shares)	5,000,000,000	5,000,000,000
Ordinary shares, shares issued (in shares)	1,082,614,740	977,151,270
Ordinary shares, shares outstanding (in shares)	1,077,702,540	972,239,070
Parent Company
Current assets
Cash and cash equivalents	$ 98,755	$ 565,981
Restricted cash, current	100,000	0
Short-term investments	330,000	0
Prepayments and other current assets	5,227	7,423
Total current assets	533,982	573,404
Investment in subsidiaries	309,901	224,954
Total assets	843,883	798,358
Current liabilities
Other current liabilities	2,985	2,240
Total current liabilities	2,985	2,240
Total liabilities	2,985	2,240
Shareholders’ equity
Ordinary shares (par value of $0.000006 per share; 5,000,000,000 shares authorized, 1,082,614,740 and 977,151,270 shares issued as of December 31, 2024 and 2023, respectively; 1,077,702,540 and 972,239,070 shares outstanding as of December 31, 2024 and 2023)	7	6
Additional paid-in capital	3,264,295	2,975,302
Accumulated deficit	(2,453,083)	(2,195,980)
Accumulated other comprehensive income	50,515	37,626
Treasury stock	(20,836)	(20,836)
Total shareholders’ equity	840,898	796,118
Total liabilities and shareholders’ equity	$ 843,883	$ 798,358
Stockholders' equity, par value and number of shares
Ordinary shares, par value (in dollars per share)	$ 0.000006	$ 0.000006
Ordinary shares, shares authorized (in shares)	5,000,000,000	5,000,000,000
Ordinary shares, shares issued (in shares)	1,082,614,740	977,151,270
Ordinary shares, shares outstanding (in shares)	1,077,702,540	972,239,070