Income Taxes - Changes to unrecognized tax benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Valuation allowance of DTA	$ 19,864,000	$ 10,662,000
Beginning balance of unrecognized tax benefits	258,000	168,000
Additions based on tax positions related to the current year	2,741,000	90,000
Ending balance of unrecognized tax benefits	2,999,000	258,000
Unrecognized tax benefits	3,000,000.0
Income tax examination, penalties and interest accrued	0	$ 0
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	59,700,000
Net operating loss carryforwards, not subject to expiration	58,100,000
Net operating loss carryforwards, subject to expiration	1,600,000
Tax credit carry forwards	4,800,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,600,000
Tax credit carry forwards	300,000
UK
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, not subject to expiration	3,000,000.0
GILTI	$ 900,000