Warrants - Issued July 3, 2013 Monte Carlo (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 July 3, 2013, Liability
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	65,000	65,000
CDTi stock price (in dollars per share)	$ 0.72	$ 0.94
Strike price (in dollars per share)	$ 1.22	$ 1.22
Expected volatility	102.30%	99.10%
Risk-free interest rate	0.80%	1.20%
Expected life in years	2 years 3 months 18 days	2 years 6 months
Warrants Issued July 3, 2013, Liability | November 23, 2015 Offering
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	94,000	94,000
CDTi stock price (in dollars per share)	$ 0.72	$ 0.94
Strike price (in dollars per share)	$ 1.22	$ 1.22
Expected volatility	92.50%	95.50%
Risk-free interest rate	1.00%	1.50%
Expected life in years	3 years 7 months 6 days	3 years 10 months 24 days