Equity Incentive Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Jan. 01, 2024	Oct. 31, 2017	Aug. 31, 2017	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 31, 2024	Feb. 29, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance				19,180,000	16,793,000	13,576,000
Stock options vesting period				48 months
Stock options vesting description				Options granted to employees on or after December 5, 2013 generally vest in installments of (i) 25% at the one-year anniversary and (ii) in either 36 equal monthly or 12 equal quarterly installments beginning in the thirteenth month after the initial vesting commencement date (as defined) subject to the employee’s continuous service with the Company.
Aggregate number of stock options granted to purchase common stock				838,000	1,300,000	2,700,000
Weighted - Average Grant Date Fair Value Per Option, Granted				$ 34.26	$ 23.62	$ 30.72
Aggregate intrinsic value of options exercised in period				$ 181,000	$ 44,800	$ 39,900
Fair market value of options vested in period				46,800	$ 59,000	53,200
Unrecognized compensation expense				$ 46,100
Estimated weighted-average period to recognize				2 years 2 months 4 days
Common stock, issued				119,556,000	110,772,000
Common stock issued at average per share price				$ 20.11
Share-based compensation expense				$ 105,945	$ 91,085	$ 70,667
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense				$ 155,500
Estimated weighted-average period to recognize				2 years 7 months 6 days
Aggregate intrinsic value of restricted grants vested				$ 55,300
Fair market value of restricted stock units vested				$ 42,200
Frist Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting percentage				25.00%
Second Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting percentage				25.00%
Third Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting percentage				25.00%
Fourth Anniversary [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting percentage				25.00%
Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issuable increased during the period	200,000
Equity Incentive Plan 2010 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance			6,188,466
Percentage of voting shares			10.00%
Options expire from issuance date			10 years
Equity Incentive Plan 2010 [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of estimated fair value per share of common stock on the date of grant			100.00%
Equity Incentive Plan 2010 [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage price of each share of the fair value on date of grant			110.00%
2017 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance		1,359,587
Percentage of voting shares		4.00%
Number of shares available for future grant		299,568		6,497,120
Shares issuable increased during the period		4,219,409
Common Stock Issuance Description				equal to the lowest of 4,219,409 shares of common stock, 4.0% of the number of shares of common stock outstanding on the first day of the fiscal year and an amount determined by the board of directors.
Common stock reserved for future issuance				16,989,000	14,271,000	11,014,000
2017 Stock Incentive Plan [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant							4,219,409
2020 Inducement Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant				354,466
Common stock reserved for future issuance				1,638,000	1,857,000	1,761,000		750,000
2020 Inducement Stock Incentive Plan [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant	1,950,000
2017 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares reserved for issuance		468,823
Percentage of voting shares				1.00%
2017 Employee Stock Purchase Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance				937,646
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage price of each share of the fair value on date of grant				85.00%
Number of shares available for future grant				552,881
Common stock reserved for future issuance				0
Percentage of earnings withheld to purchase shares of common stock				15.00%
Common stock, issued				112,064
Common stock issued at average per share price				$ 48
Cash received from issuance of purchase rights				$ 5,400
Share-based compensation expense				$ 2,100