Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock shares authorized (in shares)	50,000,000	50,000,000
Preferred stock shares issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Class A Common Stock
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock shares issued (in shares)	169,157,000	172,867,000
Common stock outstanding (in shares)	169,157,000	172,867,000
Class B Common Stock
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	500,000,000	500,000,000
Common stock shares issued (in shares)	688,000	1,490,000
Common stock outstanding (in shares)	688,000	1,490,000

Face amount or stated value per share of common stock.

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