Stockholders' Equity - Narrative (Details) - USD ($)			3 Months Ended
	Mar. 31, 2019	Oct. 09, 2018	Mar. 31, 2019	Dec. 31, 2018
Class Of Stock [Line Items]
Net proceeds from sale of common stock	$ 1,000,000
Securities Purchase Agreement
Class Of Stock [Line Items]
Purchase price per share		$ 2.35
Conversion of preferred stock to common stock		866,950
Thomas B. Pickens III | Preferred Shares | Securities Purchase Agreement
Class Of Stock [Line Items]
Shares agreed to sell upon agreement		866,950
Preferred stock, par value		$ 0.001
Common Stock
Class Of Stock [Line Items]
Shares agreed to sell upon agreement			206,000	1,277,000
Common Stock | Market Issuance Sales Agreement
Class Of Stock [Line Items]
Shares agreed to sell upon agreement	205,540
Net proceeds from sale of common stock	$ 998,057
Average sale price per share	$ 5.11
Common Stock | Other Investor | Securities Purchase Agreement
Class Of Stock [Line Items]
Shares agreed to sell upon agreement		409,645
Common stock, par value		$ 0.001
Purchase price per share		$ 2.35
Aggregate gross proceeds from agreement on sale of shares		$ 3,000,000