Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Derivative Instruments [Abstract]

Summarized volume of GRE's outstanding contracts and options

	Commodity
Settlement Dates	Electricity (In MWH)	Natural Gas (In Dth)
First quarter 2020	186,005	359,710
Second quarter 2020	95,000	138,920
Third quarter 2020	85,000	105,702
Fourth quarter 2020	44,680	83,051
First quarter 2021	—	79,500
Second quarter 2021	—	60,400
Third quarter 2021	—	45,700
Fourth quarter 2021	—	38,450
First quarter 2022	—	28,600
Second quarter 2022	—	16,450
Third quarter 2022	—	2,850
Fourth quarter 2022	—	1,450

Schedule of fair value of outstanding derivative instruments recorded as assets and liability

		December 31,
		2019		2018
Asset Derivatives	Balance Sheet Location	(in thousands)
Derivatives not designated or not qualifying as hedging instruments:
Energy contracts and options (1)	Other current assets	$	324	$	1,116
Energy contracts and options	Other assets		3		458
Total derivatives not designated or not qualifying as a hedging instruments — Assets		$	327	$	1,574
Liability Derivatives
Derivatives not designated or not qualifying as hedging instruments:
Energy contracts and options (1)	Other current liabilities	$	1,909	$	2,028
Energy Contracts and options	Other liabilities		70		320
Total derivatives not designated or not qualifying as a hedging instruments — Liabilities		$	1,979	$	2,348

(1)The Company classifies derivative assets and liabilities as current based on the cash flows expected to be incurred within the following12months.

Effects of derivative instruments on the consolidated statements of operations

		Amount of Loss  Recognized on Derivatives
		Year ended December 31,
(in thousands)		2019		2018
Derivatives not designated or not qualifying as hedging instruments	Location of Loss Recognized on Derivatives
Energy contracts and options	Cost of revenues	$	24,810	$	2,013