Stockholders' Equity - Additional Information (Detail) - USD ($)			12 Months Ended
	Jun. 16, 2015	Jan. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Preferred stock, shares authorized			10,000,000	10,000,000
Preferred stock, par value			$ 0.0001	$ 0.0001
Preferred stock, shares designated			0	0
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
Proceeds from sale of common stock		$ 117,200,000
Common stock, shares authorized			300,000,000	300,000,000
Maximum 401(k) per employee, percentage of annual salary			60.00%
Compensation expense in connection with 401(k) retirement plan			$ 900,000	$ 900,000	$ 1,000,000
Severance payment period for executives			12 months
Severance payment period for employees			6 months
Cash severance payment for chief executive officer			24 months base salary plus annual target incentive pay
Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Common stock, shares authorized			2,500,000
Percentage of purchase price of stock			85.00%
Maximum [Member]
Class of Stock [Line Items]
Matching 401(k) employer contribution, maximum amount			$ 3,000
2012 Performance Incentive Plan [Member]
Class of Stock [Line Items]
Additional new shares available for award grants	7,000,000
Share-based compensation plan's share limit reduction for every one restricted stock unit granted			1.5
2012 Performance Incentive Plan [Member] | Maximum [Member]
Class of Stock [Line Items]
Number of common stock shares available for stock options grants			19,936,433
Stock options term under equity incentive plans			8 years
2012 Performance Incentive Plan [Member] | Employee [Member]
Class of Stock [Line Items]
Service period for stock-based compensation award granted			4 years
2012 Performance Incentive Plan [Member] | Director [Member]
Class of Stock [Line Items]
Service period for stock-based compensation award granted			1 year
Restricted Stock Units (RSU) [Member]
Class of Stock [Line Items]
Awards granted			1,306,000	0	0
Restricted Stock Units (RSU) [Member] | Employee [Member]
Class of Stock [Line Items]
Service period for stock-based compensation award granted			3 years
Restricted Stock Units (RSU) [Member] | Director [Member]
Class of Stock [Line Items]
Service period for stock-based compensation award granted			1 year
2000 Non-Officer Equity Incentive Plan [Member]
Class of Stock [Line Items]
Stock options term under equity incentive plans			8 years
Common Shares [Member]
Class of Stock [Line Items]
Sale of common stock, Shares		9,775,000		9,775,000
Underwriting commission and discounts		$ 7,500,000
Legal, accounting fees, filing fees and other offering expenses		$ 600,000
Common stock, shares reserved for issuance in equity compensation plans			27,744,597