Deferred Contract Costs - Summary of Deferred Contract Costs (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Capitalized Contract Cost [Line Items]
Total deferred contract costs	$ 26.0	$ 24.1
Prepaid expenses and other current assets
Capitalized Contract Cost [Line Items]
Total deferred contract costs	3.2	4.5
Other assets
Capitalized Contract Cost [Line Items]
Total deferred contract costs	$ 22.8	$ 19.6