Fair Value Measurements - Summary of Changes in Fair Value of Level 3 Financial Instruments (Details) - Level 3 - Warrant Liability $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Balance	$ 683
Change in fair value	1,403
Reclassification of warrant liability to additional paid-in capital on conversion	(2,086)
Balance	$ 0