Income Taxes - Change in Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Income Taxes
Net change in valuation allowance	$ (1,520)	$ 3,831
Undistributed earnings	1,059	897
Withholding tax liability	168	168
Interest and penalties on uncertain tax positions	0	$ 0
Federal
Income Taxes
Operating loss carryforward	2,416
State
Income Taxes
Operating loss carryforward	2,576
Foreign
Income Taxes
Operating loss carryforward	24,491
Research and development credits \| Federal
Income Taxes
Tax credit carryforward	1,475
Research and development credits \| Federal \| CALIFORNIA
Income Taxes
Tax credit carryforward	417
Research and development credits \| Foreign
Income Taxes
Tax credit carryforward	406
Tax credits \| Foreign
Income Taxes
Tax credit carryforward	15,054
Investment tax credits \| Foreign
Income Taxes
Tax credit carryforward	$ 3,809

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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

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