DERIVATIVE INSTRUMENTS (Tables)

9 Months Ended

Sep. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location

The fair value of outstanding derivative instruments not designated as hedging instruments on the accompanying unaudited Consolidated Balance Sheets was as follows (in thousands):

Derivative Instruments	Balance Sheet Location	September 30, 2015		December 31, 2014
Contracts to purchase power	Other current liabilities	$	10,138	$	8,265
Contracts to purchase power	Other liabilities	30,175		21,103

The effect of derivative instruments not designated as hedging instruments on the accompanying unaudited Consolidated Statements of Operations was as follows (in thousands):

		Three Months Ended September 30,						Nine Months Ended September 30,
Derivative Instruments	Statement of Operations Location	2015			2014			2015			2014
Canadian dollar foreign exchange forward contracts	Gain (loss) on foreign exchange	$	—		$	—		$	—		$	(6,209	)
Contracts to purchase power	Derivative loss	(5,815		)	(23,691		)	(6,717		)	(29,621		)