Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Tax Credit Carryforward [Line Items]
Valuation allowance against a deferred tax asset related to net operating loss	$ 863,000	$ 2,140,000
Provision for federal income taxes	0
Undistributed earnings	20,600,000
Accrued interest (approximate)	100,000	100,000
Penalties accrued	$ 0	0
German
Tax Credit Carryforward [Line Items]
Valuation allowance against a deferred tax asset related to net operating loss		400,000
State Tax Credits
Tax Credit Carryforward [Line Items]
Remaining tax credit carryforward		$ 6,000,000