Revenue Recognition - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Deferred sales commissions current	$ 13,800,000		$ 13,800,000		$ 14,500,000
Deferred sales commissions noncurrent	17,500,000		17,500,000		15,900,000
Amortization expense for the deferred costs	3,200,000	$ 3,500,000	10,400,000	$ 9,200,000
Impairment loss related to costs capitalized			0		$ 0
Subscription Services, License and other
Disaggregation Of Revenue [Line Items]
Revenue recognized	78,800,000	54,300,000	138,600,000	110,700,000
Professional Services
Disaggregation Of Revenue [Line Items]
Revenue recognized	3,700,000	$ 5,100,000	9,100,000	$ 6,000,000.0
Revenue remaining performance obligation	10,800,000		10,800,000
Subscription Services And License
Disaggregation Of Revenue [Line Items]
Revenue remaining performance obligation	$ 422,700,000		$ 422,700,000