Warrants - Issued November 4, 2014 Black Scholes (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	3,613,615	4,567,207
Warrants Issued November 4, 2014, Liability
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	388,393	388,393
CDTi stock price (in dollars per share)	$ 0.72	$ 0.94
Strike price (in dollars per share)	$ 1.70	$ 1.70
Expected volatility	94.80%	96.60%
Risk-free interest rate	1.10%	1.60%
Expected life in years	4 years 2 months 12 days	4 years 4 months 24 days