Net Loss Per Share - Basic and Diluted Net Loss Per Share (Parenthetical) (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share	12.1	11.2	12.1	11.2
2024 Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of shares excluded from computation of diluted EPS	1.4	5.7	1.4	5.7
2027 Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of shares excluded from computation of diluted EPS	8.1	8.1	8.1	8.1