Net Loss per Share Attributable to Common Stockholders - Schedule of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net loss attributable to Class A and Class B common stockholders	$ (75,949)	$ (104,920)
Denominator:
Weighted average shares of common stock, basic and diluted (in shares)	123,763	111,842
Net loss per share attributable to Class A and Class B common stockholders:
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.61)	$ (0.94)