8. Stockholders’ Equity (Stock Option Assumptions) (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Weighted average of the assumptions used to value stock options on the date of grant
Weighted average expected stock price volatility	81.70%	71.40%	71.80%	72.30%
Estimated dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate	1.30%	1.80%	1.40%	1.70%
Expected life of option (in years)	6 years 72 days	6 years 108 days	6 years 72 days	6 years 108 days
Weighted average grant date fair value per option	$ 4.20	$ 30.90	$ 12.59	$ 42.60