Stockholders' Equity and Dilutive Equity Instruments - Summary of Common Shares and Creditor Warrants and Sum of Common Shares and Creditor Warrants Outstanding (Details) - shares	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Stockholders Equity Note [Line Items]
Common stock, shares outstanding	39,110,938	36,978,280	26,815,991
Total	41,741,181		30,328,407
New Creditor Warrants (Strike Price $0.001 Per Common Share)
Stockholders Equity Note [Line Items]
Creditor Warrants	1,329,884		3,512,416
GulfMark Creditor Warrants (Strike Price $0.01 Per Common Share)
Stockholders Equity Note [Line Items]
Creditor Warrants	1,300,359