Revenue - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue [Line Items]
Contract asset	$ 56.8		$ 55.2
Remaining performance obligation, description of practical expedient	In accordance with the practical expedient provided in ASC Topic 606, performance obligations that are billed and recognized as they are delivered, primarily professional services contracts that are on a time and materials basis, are excluded from the transaction price for remaining performance obligations disclosed above.
Recurring [Member]
Revenue [Line Items]
Float revenue	$ 10.7	$ 19.6

Remaining performance obligation, description of practical expedient

In accordance with the practical expedient provided in ASC Topic 606, performance obligations that are billed and recognized as they are delivered, primarily professional services contracts that are on a time and materials basis, are excluded from the transaction price for remaining performance obligations disclosed above.