Convertible Preferred Stock (Details)						1 Months Ended		3 Months Ended	12 Months Ended
	Aug. 13, 2018 USD ($) shares	Aug. 03, 2018 shares	Jul. 12, 2017 shares	Dec. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2016	Jun. 30, 2017 $ / shares shares	Jan. 31, 2017 USD ($)	Aug. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2018 shares
Convertible Preferred Stock
Proceeds from issuance of preferred stock, net | $									$ 21,060,000
Warrants
Convertible Preferred Stock
Number of warrants issued			370,370
Warrant term (in years)			5 years
Series A Convertible Preferred Stock
Convertible Preferred Stock
Dividend rate (in percentage)					3.00%
Preferred stock outstanding (in shares)									36,196,193	0
Preferred stock dividend shares issued (in shares)	669,489
Preferred stock dividend shares fair value | $	$ 1,357,000
Number of convertible preferred stock sold (in shares)				2,439,024		2,033,898		6,516,135
Price per share | $ / shares				$ 2.05		$ 2.95
Proceeds from issuance of preferred stock, gross | $				$ 5,000,000				$ 18,300,000
Proceeds from issuance of preferred stock, net | $							$ 4,500,000	$ 16,600,000
Series A Convertible Preferred Stock | Minimum
Convertible Preferred Stock
Price per share | $ / shares								$ 2.70
Series A Convertible Preferred Stock | Maximum
Convertible Preferred Stock
Price per share | $ / shares								$ 2.95
Common Stock
Convertible Preferred Stock
Ratio of reverse stock split		0.155814
Stock issued upon conversion of convertible shares		5,744,586