Stockholders' Equity - Common Stock Reserved for Future Issuance (Details)	Dec. 31, 2017 shares
Class of Stock [Line Items]
Total common shares reserved for future issuance	1,170,717
Inducement Plan
Class of Stock [Line Items]
Total common shares reserved for future issuance	12,500
Stock Option Plans
Class of Stock [Line Items]
Total common shares reserved for future issuance	618,247
Employee Stock Purchase Plan
Class of Stock [Line Items]
Total common shares reserved for future issuance	58
Options
Class of Stock [Line Items]
Total common shares reserved for future issuance	80,537
Warrants
Class of Stock [Line Items]
Total common shares reserved for future issuance	459,375