Warrants - Issued June 8, 2015 Black Scholes (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	563,998	913,441
Warrants Issued June 8, 2015, Liability
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	35,999	35,999
CDTi stock price (in dollars per share)	$ 1.65	$ 4.70
Strike price (in dollars per share)	$ 13.25	$ 13.25
Expected volatility	93.50%	102.30%
Risk-free interest rate	0.90%	1.70%
Expected life in years	4 years 4 months 24 days	4 years 10 months 24 days
November 23, 2015 Offering | Warrants Issued June 8, 2015, Liability
Fair value assumptions and methodology for assets and liabilities
Number of warrants (in shares)	63,999	63,999
CDTi stock price (in dollars per share)	$ 1.65	$ 4.70
Strike price (in dollars per share)	$ 8.50	$ 8.50
Expected volatility	96.70%	110.30%
Risk-free interest rate	1.00%	1.80%
Expected life in years	5 years	5 years 6 months