Warrants - Summary of Fair Value Assumptions for Common Stock Warrants (Details)	Dec. 31, 2018 $ / shares	Jan. 09, 2018 $ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (years)		4 years
Significant Unobservable Inputs (Level 3) | Estimated dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.00	0.00
Significant Unobservable Inputs (Level 3) | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.0246	0.0221
Significant Unobservable Inputs (Level 3) | Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected term (years)	3 years 7 days	4 years
Significant Unobservable Inputs (Level 3) | Fair value per share of common stock underlying the warrant
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.83	3.48
Significant Unobservable Inputs (Level 3) | Warrant exercise price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	4.66	4.66
Warrant | Significant Unobservable Inputs (Level 3) | Expected volatility | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	0.7774	0.7566
Warrant | Significant Unobservable Inputs (Level 3) | Expected volatility | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value assumption	1.00	1.00