Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	94 Months Ended
	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 Customer $ / shares shares	Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 USD ($) Customer $ / shares shares	Mar. 31, 2015 USD ($) Customer	Dec. 31, 2015 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Company incorporation date				Feb. 20, 2008
Entity Incorporation, State Name				Delaware
Proceeds from sale of common stock, net of underwriters' discounts and commissions					$ 120,601,000
Other-than-temporarily impaired investments				$ 0		$ 0
Goodwill impairment							$ 0
Common Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of common stock shares issued upon conversion of convertible preferred stock | shares	24,885,778
Series F Convertible Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Convertible preferred stock conversion rate | shares	1.02		1.02		1.02
Series A Through E Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Convertible preferred stock conversion rate | shares	1		1		1
Convertible Preferred Stock [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of convertible preferred stock shares converted | shares	24,813,343
Initial Public Offering [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Common stock shares issued | shares	5,750,000
Proceeds from sale of common stock, net of underwriters' discounts and commissions	$ 123,000,000
Common stock shares issued, price per share | $ / shares	$ 23.00		$ 23.00		$ 23.00
Offering expenses	$ 3,100,000
Accounts Receivable [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer				0		1
Revenue [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer		0	0	0	0
Credit Concentration Risk [Member] | Accounts Receivable [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration of risk, percentage				10.00%		12.00%
Credit Concentration Risk [Member] | Revenue [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Concentration of risk, percentage		10.00%	10.00%	10.00%	10.00%
Restatement Adjustment [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Current deferred tax liabilities		$ (900,000)		$ (900,000)			(900,000)
Non-current deferred tax liabilities		$ 900,000		$ 900,000			$ 900,000