Revenue and Contract Acquisition Costs - Summary of Deferred Revenue (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accrued expenses and other current liabilities	$ 4.3	$ 3.2
Other liabilities	0.9	1.0
Total deferred revenue	$ 5.2	$ 4.2