Quarterly Data (Unaudited) - Schedule of Quarterly Data Unaudited (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Exploratory Wells Drilled [Line Items]
Dry hole costs and impairments	$ 1,761,400		$ 155,800	$ 422,400	$ 1,967,180	$ 462,234	$ 236,930
Charge related to amendment of drilling contract					$ (95,908)
U.S. Gulf of Mexico
Exploratory Wells Drilled [Line Items]
Charge related to amendment of drilling contract		$ 95,900
Angolan
Exploratory Wells Drilled [Line Items]
Dry hole costs and impairments	$ 1,691,800
Goodfellow exploratory well and underlying leases
Exploratory Wells Drilled [Line Items]
Dry hole costs and impairments			$ 149,900
Proved oil and natural gas properties
Exploratory Wells Drilled [Line Items]
Dry hole costs and impairments				256,800
Lontra exploratory well
Exploratory Wells Drilled [Line Items]
Dry hole costs and impairments				$ 151,400