Potential Shares, Excluded from Calculation of Weighted Average Number of Shares Outstanding used for Calculation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	24,391	23,159	23,945	23,391
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	16,265	16,362	16,109	16,626
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	7,982	6,763	7,606	6,642
Employee Stock Purchase Plan Rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive potential shares	144	34	230	123