Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Oil and natural gas properties
Proved	$ 1,439,904	$ 1,463,950
Unproved	13,365	17,964
Total oil and natural gas properties	1,453,269	1,481,914
Less: accumulated depreciation, depletion and impairment	(1,370,544)	(1,375,692)
Net oil and natural gas properties	82,725	106,222
Property, Plant and Equipment, net
Financing leases	319	1,051
Total	127,544	128,236
Less accumulated depreciation and amortization	(27,972)	(25,118)
Other property, plant and equipment, net	99,572	103,118
Total property, plant and equipment, net	182,297	209,340
Land
Property, Plant and Equipment, net
Property, plant and equipment, gross	200	200
Electrical infrastructure
Property, Plant and Equipment, net
Property, plant and equipment, gross	121,819	121,819
Other non-oil and natural gas equipment
Property, Plant and Equipment, net
Property, plant and equipment, gross	1,603	1,563
Buildings and structures
Property, Plant and Equipment, net
Property, plant and equipment, gross	$ 3,603	$ 3,603

Amount of accumulated depreciation, depletion, amortization and valuation allowance relating to oil and gas producing activities.

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The sum of the capitalized costs incurred, as of the balance sheet date, of unproved properties excluded from amortization including acquisition costs, exploration costs, development costs, and production costs.

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Capitalized costs of proved properties incurred for any combination mineral interests acquisitions; wells and related equipment; support equipment and facilities; and uncompleted wells and equipment and other costs not previously disclosed within this table.

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Amount, before accumulated amortization, of right-of-use asset from finance lease.

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Oil and gas properties, gross, carried under the full cost method.

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Amount of accumulated depreciation and amortization from plant, property, and equipment and right-of-use asset from finance lease.

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Amount, after accumulated depreciation and amortization, of property, plant, and equipment and finance lease right-of-use asset.

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Amount, before accumulated depreciation and amortization, of property, plant, and equipment and finance lease right-of-use asset.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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