Stockholders' Equity - Common Stock Warrant Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Class of Warrant or Right
Outstanding warrants, beginning of period	2,768,882
Outstanding warrants, end of period	2,765,044
Warrant exercise price per share	$ 0.08	$ 0.08
Expiration Date - November 2017
Class of Warrant or Right
Exercised	(3,838)
Warrant exercise price per share	$ 0.08