401(k) Savings plan - Additional Information (Detail) - 401 (k) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Contributions to the 401(k) plan		$ 4.6
Expenses related to 401(k) plan			$ 5.2	$ 4.6	$ 2.4
Scenario, Forecast
Defined Contribution Plan Disclosure [Line Items]
Contributions to the 401(k) plan	$ 5.2