Note 2 - Long-term Debt (Details Textual) - USD ($)		3 Months Ended	9 Months Ended
	May 25, 2017	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Debt Instrument, Maturity Date, Percentage of Conversion Rate,	120.00%
Gain (Loss) on Extinguishment of Debt			$ (3,501,000)	$ (2,250,000)
Warrants [Member] | Interest Expense [Member]
Unrealized Gain (Loss) on Derivatives		$ 421,000,000	$ (3,600,000)
2017 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	357,500	357,500	357,500
Warrants and Rights Outstanding	$ 2,900,000	$ 2,900,000	$ 2,900,000
Warrant Term	5 years
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 14.94
Senior Secured Debt [Member]
Debt Instrument, Fee Amount	$ 60,000,000
Debt Instrument, Additional Amount after Refinance	15,000,000
Debt Instrument, Maturity Date, Minimum Principal Outstanding Amount	$ 10,000,000
Debt Instrument, Payment-in-kind Rate	6.00%
Debt Instrument, Cash Rate	2.00%
Upfront Fee, Recorded as Additional Debt Discount, Percentage	2.00%
Debt Instrument, Maturity Date, Description	The New Senior Secured Debt will mature on the earliest of (a) the four year anniversary of the Closing Date, and (b) the “Springing Maturity Date”, which is defined as the date which is 91 days prior to the maturity date of the 7.00% Convertible Senior Notes of Cadiz due 2020 (the “New Convertible Notes”) that were issued in December 2015 and April 2016 pursuant to the New Convertible Notes Indenture as defined in the Credit Agreement, if on the 91st day preceding the maturity date of the New Convertible Notes, the 5-Day VWAP, as defined in the Credit Agreement, is less than 120% of the then applicable Conversion Rate, as defined in the New Convertible Notes Indenture, and at least $10,000,000 in original principal amount of the New Convertible Notes is outstanding ((a) or (b), as applicable, the “Maturity Date”).
Senior Secured Debt [Member] | Legal and Finders fees [Member]
Debt Instrument, Unamortized Discount	$ 1,500,000
Prior Senior Secured Debt [Member]
Extinguishment of Debt, Amount	45,000,000
Gain (Loss) on Extinguishment of Debt	$ (3,500,000)
2020 Convertible Senior Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	7.00%