Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Stock Options - Additional Information (Detail) (USD $)	12 Months Ended					1 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2012 2007 Equity Incentive Plan [Member]	May 31, 2007 2007 Equity Incentive Plan [Member]	Dec. 31, 2013 2013 Equity Incentive Award Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance	1,069,250	2,576,252					450,000	510,000
Options available for future grant	501,500	0				0
Additional common stock reserved for issuance								300,000
Shares of common stock available for issuance description								In addition, the number of shares of common stock available for issuance under the 2013 Plan will be annually increased on the first day of each fiscal year during the term of the 2013 Plan, beginning with the 2014 fiscal year, by an amount equal to the least of (i) 300,000 shares; (ii) four percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company's board of directors may determine.
Reserve percentage for issuance of shares								4.00%
Options available for future grant								8,500
Options granted, weighted average term				7 years	10 years
Options granted, vesting period				3 years	4 years
Intrinsic value, common stock price	$ 7.45	$ 0.40
Stock options exercised	326,750
Stock options vested	230,500	215,500
Total intrinsic value of stock options exercised	$ 0	$ 0	$ 0
Weighted average grant date fair value per share	$ 6.33	$ 0.00	$ 0.05