Business Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2019

Business Segment and Geographic Information [Abstract]

Schedule of operating results for the business segments

	GRE		GRE International			GES			GOGAS			Corporate			Total
	(in thousands)
Year ended December 31, 2019
Revenues	$	286,611	$	16,595		$	12,085		$	—		$	—		$	315,291
Income (loss) from operations		27,176		(8,133	)		(2,895	)		(1,028	)		(5,295	)		9,825
Depreciation and amortization		703		1,819			1,047			57			1			3,627
Impairment of goodwill		—		—			(400	)		—			—			(400	)
Equity in the net loss of equity method investees		—		4,440			—			291			99			4,830
Year ended December 31, 2018
Revenues	$	274,443	$	—		$	5,696		$	170		$	—		$	280,309
Income (loss) from operations		28,988		(1,201	)		(982	)		(6,532	)		(8,295	)		11,978
Depreciation and amortization		1,538		1			178			345			—			2,062
Exploration		—		—			—			244			—			244
Write-off of capitalized exploration costs		—		—			—			2,742			—			2,742
Equity in the net loss of Shoreditch		—		2,990			—			440			—			3,430

Schedule of total assets for the business segments

(in thousands)	GRE		GRE International		GES		GOGAS		Corporate		Total
	(in thousands)
Total assets:
December 31, 2019	$	105,937	$	11,468	$	19,383	$	10,873	$	8,583	$	156,244
December 31, 2018		113,918		3,654		11,519		15,375		2,398		146,864
Investments in equity method investees:
December 31, 2019	$	—	$	—	$	—	$	275	$	400	$	675
December 31, 2018		—		1,679		—		529		—		2,208

Schedule of revenues from customers located outside of the united states

	United  States		Foreign Countries		Total
	(in thousands)
Year ended December 31, 2019	$	16,595	$	—	$	16,595
Year ended December 31, 2018		—		170		170

Schedule of net long-lived assets and total assets held outside of the United States

	United States		Foreign Countries		Total
	(in thousands)
December 31, 2019
Long-lived assets, net	$	17,498	$	4,440	$	21,938
Total assets		143,738		12,506		156,244
December 31, 2018
Long-lived assets, net	$	20,529	$	1,409	$	21,938
Total assets		141,336		5,528		146,864