Common Stock and Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	May. 31, 2014	Aug. 31, 2013	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2015
Class of Stock [Line Items]
Preferred stock, shares authorized	10,000,000				10,000,000
Preferred stock, par value	$ 0.001				$ 0.001
Common stock, shares authorized	100,000,000				100,000,000		100,000,000
Common stock, par value	$ 0.001				$ 0.001		$ 0.001
Fair value granted restricted stock awards shares of common stock					522,000
Grant date fair value of restricted stock awards, per share					$ 30.93
Stock-based compensation expense					$ 4,659	$ 1,931
Stock options granted					391,000
Stock-based compensation cost expected to be recognized over weighted-average period					3 years 4 months 24 days
Unrecognized stock-based compensation cost related to outstanding unvested stock awards	$ 33,300				$ 33,300
Expected to vest unrecognized stock-based compensation cost related to outstanding unvested stock options	$ 39,600				$ 39,600
Stock based compensation cost is expected to be recognized over a weighted-average period					2 years 9 months 18 days
Nonemployees [Member]
Class of Stock [Line Items]
Stock-based compensation expense					$ 200	$ 100
Stock options granted					4,301	14,300
Restricted Stock Awards [Member]
Class of Stock [Line Items]
Fair value granted restricted stock awards shares of common stock			40,000	100,000
Fair value of the restricted stock awards, value			$ 700	$ 900
Grant date fair value of restricted stock awards, per share			$ 16.93	$ 9.37
Common stock vesting period			4 years	4 years
Stock-based compensation expense					$ 100	$ 100
2014 Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Shares reserved for issuance under plan	1,000,000				1,000,000
Additional shares available for issuance under the plan		500,000
Percentage of common stock shares increased under the plan		1.00%
Shares available for issuance	1,471,169				1,471,169
2014 Equity Incentive Plan [Member]
Class of Stock [Line Items]
Shares reserved for issuance under plan		5,000,000
Shares available for issuance	6,745,182				6,745,182
Shares available for grant under plan		5,184,878
Increase in shares available under plan, percentage of outstanding common stock shares		5.00%
2008 Equity Incentive Plan [Member]
Class of Stock [Line Items]
Shares available for issuance	0				0
Before Amendment and Restated [Member]
Class of Stock [Line Items]
Common stock, shares authorized	55,000,000				55,000,000
Common Stock [Member]
Class of Stock [Line Items]
Number of common stock shares issued upon conversion of convertible preferred stock	24,885,778	24,885,778