Related Party Transactions with its Significant Investor - Additional Information (Details) - USD ($)			1 Months Ended		3 Months Ended	4 Months Ended	6 Months Ended
	Sep. 20, 2019	Sep. 19, 2019	Jun. 30, 2019	Apr. 30, 2019	Jun. 30, 2019	Apr. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Related Party Transaction [Line Items]
Accrued interest on related party loan								$ 270,000
IPO
Related Party Transaction [Line Items]
Issuance of common stock, shares	12,578,125
Common Stock
Related Party Transaction [Line Items]
Issuance of common stock, shares					7,565
Shares issued upon conversion of convertible preferred stock		10,787,861
Non-voting Common Stock
Related Party Transaction [Line Items]
Shares issued upon conversion of convertible preferred stock	6,431,205
Haldor Topsøe Holding A/S and Holdco
Related Party Transaction [Line Items]
Proceeds from related party notes receivable				$ 2,500,000
Haldor Topsøe Holding A/S and Holdco | Common Stock | IPO
Related Party Transaction [Line Items]
Issuance of common stock, shares	1,250,000						10,289,453
Haldor Topsøe Holding A/S and Holdco | Series C Convertible Preferred Stock
Related Party Transaction [Line Items]
Preferred stock issued			2,269,838
Preferred stock issued, value			$ 30,000,000
Debt settled			20,000,000		$ 20,000,000			20,000,000
Haldor Topsøe Holding A/S and Holdco | Non-voting Common Stock | IPO
Related Party Transaction [Line Items]
Shares issued upon conversion of convertible preferred stock	2,269,838
Haldor Topsøe Holding A/S and Holdco | Unsecured Promissory Note
Related Party Transaction [Line Items]
Proceeds from loan from related party						$ 15,000,000
Outstanding unsecured promissory note			$ 20,000,000		20,000,000			20,000,000
Accrued interest on related party loan					$ 200,000			$ 300,000