FINANCIAL INSTRUMENTS 3 (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Finance obligation to ACB Energy Partners LLC	$ 21,150,000	$ 21,646,000
Estimated fair value of long-term debt	649,700,000	682,300,000
Carrying amount of long-term debt	626,400,000	626,400,000
Energenic US LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity interest of Marina in Energenic	50.00%
Marina Energy LLC [Member] | Energenic US LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity interest of Marina in Energenic	50.00%
Other construction costs	23,600,000	23,600,000
Finance obligation to ACB Energy Partners LLC	$ 21,100,000	$ 21,600,000