Organization and Significant Accounting Policies - Summary of Anti-dilutive Securities Excluded from Calculation of Weighted Average Common Shares Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Warrants to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	10,000,000	0
Stock options | 2008 and 2016 Plans
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	1,671,666	1,399,484
Stock options | Inducement Options Outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	100,500	0