Description of the Business and Summary of Significant Accounting Policies - Deferred Commissions, Net (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Capitalized Contract Cost [Line Items]
Additional contract costs deferred	$ 8,600,000	$ 7,400,000	$ 27,600,000	$ 21,100,000
Deferred contract costs, amortization period	5 years		5 years
Amortization of deferred commissions	$ 6,700,000	4,600,000	$ 17,500,000	12,700,000
Impairment loss related to deferred costs	0	$ 0	0	$ 0
Deferred Commissions | Prepaid Expenses and Other Current Assets
Capitalized Contract Cost [Line Items]
Deferred contract costs	25,300,000		25,300,000		$ 19,900,000
Deferred Commissions | Other Assets
Capitalized Contract Cost [Line Items]
Deferred contract costs	$ 48,200,000		$ 48,200,000		$ 43,500,000