Stockholders' Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		1 Months Ended
	Jan. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Jan. 30, 2014
Schedule Of Stockholders Equity [Line Items]
Common stock issued to settle liability	50,330
Stock Option [Member]
Schedule Of Stockholders Equity [Line Items]
Common stock issued upon the exercise of stock options		1,429	16,964
Restricted Stock Units (RSUs) [Member]
Schedule Of Stockholders Equity [Line Items]
Common stock upon the vesting of restricted stock units		88,184	29,999
Patents [Member]
Schedule Of Stockholders Equity [Line Items]
Additional acquired technology rights				$ 5.0
CircuLite [Member]
Schedule Of Stockholders Equity [Line Items]
Shares registered for issuance for acquisition					530,816
Shares reserved in connection with future contingent milestone payments		248,872