Revenue from Contracts with Customer - Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 96,614	$ 66,187	$ 265,542	$ 176,658
Subscription services
Disaggregation of Revenue [Line Items]
Revenue	94,312	64,258	257,827	171,869
Professional services
Disaggregation of Revenue [Line Items]
Revenue	$ 2,302	$ 1,929	$ 7,715	$ 4,789

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details