Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Number of Shares
Beginning balance (in shares)	7,373,678
Granted (in shares)	0	0	0
Exercised (in shares)	(4,322,711)	(277,729)	(2,202,895)
Forfeited (in shares)	(28,500)
Ending balance (in shares)	3,022,467	7,373,678
Exercisable (in shares)	3,022,467
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 1.96
Granted (in dollars per share)	0
Exercised (in dollars per share)	0.29
Forfeited (in dollars per share)	10.93
Ending balance (in dollars per share)	4.27	$ 1.96
Exercisable (in dollars per share)	$ 4.27
Aggregate grant date fair value, outstanding at December 31, 2020	$ 7
Issued, aggregate grant date fair value	0
Exercised, aggregate grant date fair value	0
Forfeited, aggregate grant date fair value	0
Aggregate grant date fair value, outstanding at December 31, 2021	7	$ 7
Aggregate grant date fair value, exercisable	$ 7