Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			6 Months Ended
	Apr. 09, 2019	Apr. 02, 2019	Jun. 30, 2019	Dec. 31, 2018
Description Of Business And Basis Of Presentation [Line Items]
Proceeds from issuance of common stock in initial public offering, net of issuance costs			$ 2,484,230
Common stock shares authorized				340,000,000
Preferred stock shares authorized		1,000,000,000	1,000,000,000	0
Common stock shares outstanding				22,438,472
Class A Common Stock
Description Of Business And Basis Of Presentation [Line Items]
Underwriting discounts and commissions		$ 70,300
Offering costs		$ 7,700
Common stock shares authorized		18,000,000,000	18,000,000,000
Common stock shares outstanding		255,007,393	279,970,833
Redeemable Convertible Preferred Stock
Description Of Business And Basis Of Presentation [Line Items]
Conversion of stock, shares converted		219,175,709
Class B Common Stock
Description Of Business And Basis Of Presentation [Line Items]
Common stock shares authorized		100,000,000	100,000,000	0
Common stock shares outstanding		12,779,709	12,779,709	0
IPO | Class A Common Stock
Description Of Business And Basis Of Presentation [Line Items]
Number of shares issued		32,500,000
Price per share		$ 72.00
Proceeds from issuance of common stock in initial public offering, net of issuance costs		$ 2,500,000
Exercise by Underwriters' Option to Purchase Additional Shares | Class A Common Stock
Description Of Business And Basis Of Presentation [Line Items]
Number of shares issued	2,996,845
Price per share	$ 72.00