Net Loss per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Earnings per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders	$ (26,135)	$ (19,706)	$ (58,881)	$ (36,820)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	299,321	85,683	297,392	85,382
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.09)	$ (0.23)	$ (0.20)	$ (0.43)
Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders		$ (19,706)		$ (36,820)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)		85,683		85,382
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)		$ (0.23)		$ (0.43)
Class A common stock | Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders	$ (14,773)		$ (26,404)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	169,194		133,359
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.09)		$ (0.20)
Class B common stock | Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to common stockholders	$ (11,362)		$ (32,477)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	130,127		164,033
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.09)		$ (0.20)