Net Income (Loss) per Share - dilutive (Details)	12 Months Ended
	Dec. 31, 2014 shares
Weighted Average Number Diluted Shares Outstanding Adjustment [Line Items]
Total Weighted Average Outstanding Common Stock equivalents	1,515,749
Outstanding common stock options
Weighted Average Number Diluted Shares Outstanding Adjustment [Line Items]
Total Weighted Average Outstanding Common Stock equivalents	1,494,796
Outstanding warrants
Weighted Average Number Diluted Shares Outstanding Adjustment [Line Items]
Total Weighted Average Outstanding Common Stock equivalents	5,433
RSUs
Weighted Average Number Diluted Shares Outstanding Adjustment [Line Items]
Total Weighted Average Outstanding Common Stock equivalents	14,128
Employee Stock Purchase Plan
Weighted Average Number Diluted Shares Outstanding Adjustment [Line Items]
Total Weighted Average Outstanding Common Stock equivalents	1,392