Fair Value Measurements - Fair Value Measurements, Valuation Techniques (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair value of common stock	$ 0.33	$ 0.40
Volatility [Member] | Minimum [Member]
Fair value measurements valuation techniques, percent	63.58%	109.30%
Volatility [Member] | Maximum [Member]
Fair value measurements valuation techniques, percent	91.93%	122.22%
Risk Free Interest Rate [Member] | Minimum [Member]
Fair value measurements valuation techniques, percent	2.36%	1.03%
Risk Free Interest Rate [Member] | Maximum [Member]
Fair value measurements valuation techniques, percent	2.59%	1.27%
Exercise Price [Member] | Minimum [Member]
Fair value measurements valuation techniques, exercise price	$ 0.75	$ 0.75
Exercise Price [Member] | Maximum [Member]
Fair value measurements valuation techniques, exercise price	$ 1.37	$ 1.37
Expected Life [Member] | Minimum [Member]
Fair value measurements valuation techniques, term	5 months 12 days	11 months 19 days
Expected Life [Member] | Maximum [Member]
Fair value measurements valuation techniques, term	11 months 26 days	1 year 11 months 26 days