XML 44 R33.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies (Details) - USD ($)
9 Months Ended 12 Months Ended
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Concentration Risk [Line Items]        
Marketing promotions and discounts , as a reduction of revenue   $ 51,300,000 $ 27,700,000 $ 11,600,000
Marketing promotions and discounts , as sales and marketing expense   91,500,000 45,200,000 18,700,000
Advertising expenses   136,800,000 53,500,000 25,300,000
Redeemable convertible preferred stock redemption $ 866,000,000   $ 62,500,000 $ 18,800,000
Letter of credit        
Concentration Risk [Line Items]        
Restricted cash is comprised of $2.9 million which is pledged in the form of a letter of credit for the Company's new headquarters in San Francisco   $ 2,900,000    
Revenue | Developer partners        
Concentration Risk [Line Items]        
Number of developer partners   2 2 2
Revenue | Developer partner one        
Concentration Risk [Line Items]        
Percentage of revenue   59.00% 83.00% 70.00%
Revenue | Developer partner two        
Concentration Risk [Line Items]        
Percentage of revenue   28.00% 7.00% 16.00%