Stockholders' Equity (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014
Options
Outstanding at the beginning of the period (in shares)	2,548,314	1,820,784	1,820,784
Granted (in shares)	193,000	876,500
Exercised (in shares)		(50,304)
Canceled (in shares)	(89,792)	(98,666)
Outstanding at the end of the period (in shares)	2,651,522	2,548,314	2,651,522
Weighted-Average Exercise Price (Per Share)
Outstanding at the beginning of the period (in dollars per share)	$ 4.77	$ 4.46	$ 4.46
Granted (in dollars per share)	$ 2.08	$ 5.37
Exercised (in dollars per share)		$ 1.18
Canceled (in dollars per share)	$ 5.93	$ 6.35
Outstanding at the end of the period (in dollars per share)	$ 4.53	$ 4.77	$ 4.53
Weighted-average fair value of options granted during the period	$ 1.39		$ 3.08
Equity Incentive Plan Twenty Twelve [Member]
Stock-Based Compensation Plans
Vesting period			4 years
Vesting period expiration			10 years
Employee Stock Purchase Plan Twenty Twelve [Member]
Stock-Based Compensation Plans
Look-back period for payroll deductions to acquire ownership interest			6 months
Weighted-Average Exercise Price (Per Share)
Fair market value percentage of ordinary shares	85.00%		85.00%
Number of shares authorized to be issued under the plan, before 2001 Plan additions	168,469		168,469