Stockholders' Equity - eXponential Stock Performance Plan (Details) $ in Millions			3 Months Ended
	Feb. 12, 2019 USD ($) item tranche	May 24, 2018 USD ($) shares	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
First tranche		$ 2,500.0
Market capitalization goal increment		$ 1,000.0
Recorded share-based compensation expense			$ 132.4
Number of options expected to vest | shares			5,800,000
eXponential Stock Units | 2019 eXponential Stock Performance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares			10,000	43,000
Expiration period	9 years
Number of vesting tranches of share-based awards | tranche	12
First tranche	$ 2,500.0
Number of performance goals, revenue | item	8
Number of performance goals, adjusted EBITDA | item	8
Market capitalization goal increment	$ 1,000.0
Anti-dilution provision, maximum shares growth rate per year			3.00%
Recorded share-based compensation expense			$ 94.8
Unrecognized stock-based compensation expense			$ 96.7
Weighted average period over which costs are recognized			3 years
eXponential Stock Units | 2019 eXponential Stock Performance Plan | Eleven Operational Goals
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options expected to vest | shares			4,900,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares		6,365,856
Weighted average period over which costs are recognized			3 years 2 months 1 day