Stockholders' Equity, Preferred Stock and Common Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Class of Stock Disclosures [Abstract]
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares issued on exercise of options (in shares)	32,932,273	29,943,086
Common stock, shares outstanding (in shares)	32,932,273	29,943,086
Series C Convertible Preferred Stock [Member]
Class of Stock Disclosures [Abstract]
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Beneficial ownership percentage	9.99%
Preferred stock, stated value (in dollars per share)	$ 1,000
Preferred stock conversion price (in dollars per share)	$ 2.69
Number of common shares issuable on conversion of preferred stock (in shares)	15,049,000
Preferred stock, shares issued (in shares)	2,103	9,968
Preferred stock, shares outstanding (in shares)	2,103	9,968
Number of common shares issued on conversion of preferred stock (in shares)	2,923,791	9,744,916