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Basis of Presentation and Summary of Significant Accounting Policies - Certain Risks and Concentrations (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Customer concentration risk | Distributor To The U.S. Navy | Revenue
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)	30.00%	40.00%	41.00%	39.00%
Customer concentration risk | Distributor To The U.S. Navy | Accounts receivable
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)			43.00%		28.00%
Customer concentration risk | Regional Commercial Lighting Retrofit Company | Revenue
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)	10.00%	15.00%	11.00%	15.00%
Customer concentration risk | Regional Commercial Lighting Retrofit Company | Accounts receivable
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)			10.00%
Customer concentration risk | Shipbuilder For U.S. Navy | Revenue
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)		11.00%
Customer concentration risk | Shipbuilder For U.S. Navy | Accounts receivable
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)					21.00%
Customer concentration risk | Distributor To The U.S. Navy Combined With Sales To Shipbuilders | Revenue
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)	35.00%	60.00%	47.00%	53.00%
Supplier concentration risk | Offshore Supplier | Accounts Payable
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)			68.00%		44.00%
Supplier concentration risk | Offshore Supplier | Total Expenditures
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)	39.00%	12.00%	32.00%	15.00%
Supplier concentration risk | Domestic Supplier | Total Expenditures
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)		14.00%
Geographic concentration risk | Revenue | Countries outside of the United States
Concentration Risk [Line Items]
Concentration risk (less than for geographic concentration risk)	3.00%	1.00%	2.00%	1.00%

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