Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
PRC income tax rate				25.00%
Withholding income tax rate				10.00%
Withholding tax on dividends rate				5.00%
Cumulative tax loss carryforwards		$ 26,800,000
Valuation allowance increased (decreased)		18,300,000
Uncertain tax positions	$ 0		$ 0
United States
Operating Loss Carryforwards [Line Items]
Cumulative tax loss carryforwards		99,300,000	83,100,000
PRC
Operating Loss Carryforwards [Line Items]
Cumulative tax loss carryforwards		$ 24,000,000.0	$ 28,300,000