Oil and Gas Properties and Equipment - Schedule of Oil and Gas Properties and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Proven Properties:
Acquisition, equipment, exploration, drilling and abandonment costs	$ 11,158,940	$ 10,752,642
Less: Accumulated depletion, depreciation and amortization	(9,843,820)	(9,742,176)
Proven	$ 1,315,120	$ 1,010,466

Oil and gas properties, net of depletion, carried under the full cost method.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant