Stockholders' Equity - Common Stock Warrants (Details) - $ / shares	1 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2018
Convertible Preferred Stock
Number of shares after conversion of issued warrants (in shares)		2,454
June 2018 common stock warrants
Convertible Preferred Stock
Number of warrants issued	4,200,000
Exercise price of warrants (in dollars per share)	$ 12.00
Warrants term	5 years
Weighted average remaining contractual life		4 years 5 months 19 days
Initial public offering | Credit Facility
Convertible Preferred Stock
Number of shares after conversion of issued warrants (in shares)		122.12
Weighted average contractual life		2 years 11 months 12 days