Deferred Revenue and Performance Obligations - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Deferred Revenue Arrangement [Line Items]
Percentage of revenue expected to be recognized from remaining performance obligation			90.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	24 months		24 months
Subscription
Deferred Revenue Arrangement [Line Items]
Recognition of deferred revenue	$ 44.7	$ 34.5	$ 74.0	$ 61.1
Revenue expected to be recognized from remaining performance obligation	226.9		226.9
Professional Services
Deferred Revenue Arrangement [Line Items]
Recognition of deferred revenue	2.4	$ 1.6	5.3	$ 4.4
Revenue expected to be recognized from remaining performance obligation	$ 12.1		$ 12.1