Income Taxes - Income tax - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 9.2	$ 6.2
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 4.5	$ 3.0