Common Stock and Stockholders' Equity - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Number of options
End number of options (in shares), outstanding	3,098
Stock options
Number of options
Beginning number of options (in shares), outstanding	59
Number of options, Granted (in shares)	3,224
Number of options, Exercised (in shares)	(3)
Number of options, Canceled/forfeited/expired (in shares)	(182)
End number of options (in shares), outstanding	3,098
Number of options, Exercisable (in shares)	237
Weighted average exercise price
Beginning, Weighted average exercise price, Options outstanding (in dollars per share) | $ / shares	$ 45.60
Weighted average exercise price, Granted (in dollars per share) | $ / shares	0.68
Weighted average exercise price, Exercised (in dollars per share) | $ / shares	0.95
Weighted average exercise price, Canceled/forfeited/expired (in dollars per share) | $ / shares	6.81
Ending, Weighted average exercise price, Options outstanding (in dollars per share) | $ / shares	1.17
Weighted average exercise price, Exercisable (in dollars per share) | $ / shares	$ 6.78
Weighted average remaining contractual term
Weighted average remaining contractual term, Options outstanding	9 years 6 months 29 days
Weighted average remaining contractual term, Exercisable	8 years 6 months 7 days
Aggregate intrinsic value
Aggregate intrinsic value, Options outstanding | $	$ 703
Aggregate intrinsic value, Exercisable | $	$ 35