Fair Value Measurements (Details 2-Nonrecurring) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Impairments	$ 24	$ 75	$ 229
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	56	113	179
Assets, Fair Value Adjustment	$ 24	$ 75	229
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | International Exploration and Production [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure			103
Impairments			136
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Gulf of Mexico Assets [Member]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Financial Statement [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure			76
Impairments			$ 89