Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] Underwritten Public Offering [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] January 2021 Inducement Warrants [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] Warrants to Purchase Common Stock [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] Exchange Warrants [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Preferred Stock [Member] Series A Convertible Preferred Stock [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] Underwritten Public Offering [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] January 2021 Inducement Warrants [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] Warrants to Purchase Common Stock [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] Exchange Warrants [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Preferred Stock [Member] Series B-1 Convertible Preferred Stock [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] Underwritten Public Offering [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] January 2021 Inducement Warrants [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] Warrants to Purchase Common Stock [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] Exchange Warrants [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Preferred Stock [Member] Series B-2 Convertible Preferred Stock [Member] | Preferred Stock [Member] Undesignated Preferred Stock [Member] | Undesignated Preferred Stock [Member] Underwritten Public Offering [Member] | Undesignated Preferred Stock [Member] January 2021 Inducement Warrants [Member] | Undesignated Preferred Stock [Member] Warrants to Purchase Common Stock [Member] | Undesignated Preferred Stock [Member] Exchange Warrants [Member] | Undesignated Preferred Stock [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Undesignated Preferred Stock [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Undesignated Preferred Stock [Member] | Common Stock [Member] Underwritten Public Offering [Member] | Common Stock [Member] January 2021 Inducement Warrants [Member] | Common Stock [Member] Warrants to Purchase Common Stock [Member] | Common Stock [Member] Exchange Warrants [Member] | Common Stock [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Common Stock [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Common Stock [Member] | Additional Paid-in Capital [Member] Underwritten Public Offering [Member] | Additional Paid-in Capital [Member] January 2021 Inducement Warrants [Member] | Additional Paid-in Capital [Member] Warrants to Purchase Common Stock [Member] | Additional Paid-in Capital [Member] Exchange Warrants [Member] | Additional Paid-in Capital [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Additional Paid-in Capital [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Additional Paid-in Capital [Member] | Retained Earnings [Member] Underwritten Public Offering [Member] | Retained Earnings [Member] January 2021 Inducement Warrants [Member] | Retained Earnings [Member] Warrants to Purchase Common Stock [Member] | Retained Earnings [Member] Exchange Warrants [Member] | Retained Earnings [Member] Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Retained Earnings [Member] Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Retained Earnings [Member] | Treasury Stock [Member] | Underwritten Public Offering [Member] | January 2021 Inducement Warrants [Member] | Warrants to Purchase Common Stock [Member] | Exchange Warrants [Member] | Conversion of Facility Notes into Series B-2 Preferred Stock [Member] | Conversion of Series B-2 Preferred Stock into Common Stock [Member] | Total |