Australia Research and Development Tax Incentive - Additional Information (Detail) - Spero Potentiator Australia Pty Limited [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Australia [Member]
Schedule Of Income Tax [Line Items]
Tax incentive receivable	$ 0.4		$ 1.2
Research and Development Expenses [Member]
Schedule Of Income Tax [Line Items]
Percentage of refundable tax incentive	43.50%
Reduction to research and development expenses		$ 0.2