Stockholders' Equity - eXponential Stock Performance Plan (Details) $ in Millions			3 Months Ended	9 Months Ended
	Feb. 12, 2019 USD ($) item tranche	May 24, 2018 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2021 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market capitalization goal for such tranche		$ 2,500.0
Market capitalization goal increment		$ 1,000.0
Recorded share-based compensation expense				$ 219.5
Number of awards expected to vest | shares			1,600,000	1,600,000
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			8,000	40,000
Expiration period	9 years
Number of vesting tranches of share-based awards | tranche	12
Market capitalization goal for such 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				$ 161.4
Number of awards expected to vest | shares			1,800,000	1,800,000
Unrecognized stock-based compensation expense			$ 34.6	$ 34.6
Weighted average period over which costs are recognized				2 years 1 month 13 days
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				1 year 6 months 10 days