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Stockholders' Equity - Common Stock (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2017 $ / shares shares	Dec. 31, 2018 vote $ / shares shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2016 shares
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares	$ 0.00001	$ 0.00001	$ 0.00001
Restricted Stock
Class of Stock [Line Items]
Shares granted (in shares)		16,200,000	21,500,000	16,600,000
Co-Founder Grants | Restricted Stock
Class of Stock [Line Items]
Shares granted (in shares)	14,700,000	14,700,000	14,700,000
Class A common stock
Class of Stock [Line Items]
Votes per share | vote		1
Common stock, shares authorized (in shares)	533,300,000.0	2,400,000,000.0	533,300,000.0
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001
Common stock, shares issued (in shares)	8,900,000	211,000,000	8,900,000
Common stock, shares outstanding (in shares)	8,900,000	211,000,000	8,900,000
Class B common stock
Class of Stock [Line Items]
Votes per share | vote		10
Shares converted in conversion (in shares)		157,000,000
Common stock, shares authorized (in shares)	466,700,000.0	475,000,000.0	466,700,000.0
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001
Common stock, shares issued (in shares)	187,900,000	198,600,000	187,900,000
Common stock, shares outstanding (in shares)	187,900,000	198,600,000	187,900,000
Class C common stock
Class of Stock [Line Items]
Votes per share | vote		0
Common stock, shares authorized (in shares)	0	800,000,000.0	0
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001
Common stock, shares issued (in shares)	0	0	0
Common stock, shares outstanding (in shares)	0	0	0

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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