Stockholders' Equity - Additional Information (Detail) - USD ($)			12 Months Ended
	Jun. 26, 2018	Apr. 03, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Sale of common stock (in shares)				8,285,000
Stock issued during period subject to lock-up and stand-still provisions period		5 years
Number of shares to be issued upon exercise of outstanding options or vesting of RSUs			19,817,000
Number of shares available for issuance under equity compensation plans			9,145,000
Common stock, shares authorized (in shares)			300,000,000	300,000,000
Maximum 401(k) per employee, percentage of annual salary			60.00%
Matching 401(k) employer contribution, maximum amount			$ 6,000
Compensation expense in connection with 401(k) retirement plan			$ 3,500,000	$ 2,800,000	$ 1,600,000
Change in control severance payment period for executives			12 months
Change in control severance payment period for employees			6 months
Employee Stock Purchase Plan
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			2,500,000
Percentage of purchase price of stock			85.00%
2017 Performance Incentive Plan
Class of Stock [Line Items]
Number of common stock shares available for stock options grants			8,300,000
Number of additional shares available for award grants	10,900,000
Share-based compensation plan's share limit reduction for every one restricted stock unit granted			1.5
Stock options term under equity incentive plans			8 years
2012 Plan
Class of Stock [Line Items]
Number of additional shares available for award grants			7,000,000
Common Shares
Class of Stock [Line Items]
Sale of common stock (in shares)		8,284,600
Common stock, shares reserved for issuance in equity compensation plans			28,962,018
Employee | 2017 Performance Incentive Plan | Shares of Common Stock Underlying Outstanding Stock Options
Class of Stock [Line Items]
Service period for stock-based compensation award granted			4 years
Employee | 2017 Performance Incentive Plan | Restricted Stock Units (RSU)
Class of Stock [Line Items]
Service period for stock-based compensation award granted			3 years
Director | 2017 Performance Incentive Plan | Shares of Common Stock Underlying Outstanding Stock Options
Class of Stock [Line Items]
Service period for stock-based compensation award granted			1 year
Director | 2017 Performance Incentive Plan | Restricted Stock Units (RSU)
Class of Stock [Line Items]
Service period for stock-based compensation award granted			1 year