Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2017
SEYCHELLES | Grant
Other Commitments [Line Items]
Regulated Operating Revenue, Other					$ 0.8
Period For Which The Performance Obligation Must Be Maintained					5 years
Royalty Agreement On Future Sales
Other Commitments [Line Items]
Payment of Royalties	$ 0.1	$ 0.2	$ 0.2	$ 0.2