Employee Benefit Obligations - General (Details) - USD ($) $ in Millions	1 Months Ended
	Oct. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Liability
Underfunded defined benefit pension liabilities		$ 918	$ 954
Less current portion		(24)	(25)
Long-term defined benefit pension liabilities		894	929
Long-term retiree medical liabilities		156	157
Deferred compensation plans		362	291
Other		74	78
Total employee benefit obligations		1,486	1,455
Amounts recognized in the consolidated balance sheets
Long-term pension assets		437	559
Defined Benefit Pension Plans
Amounts recognized in the consolidated balance sheets
Long-term pension assets		437	559
Defined benefit pension liabilities		(918)	(954)
Net amount recognized		(481)	(395)
US Plan | Defined Benefit Pension Plans
Amounts recognized in the consolidated balance sheets
Defined benefit pension liabilities		(647)	(678)
Net amount recognized		(647)	(678)
Annuitized Unfunded Obligation		32	30
Annuitized Unfunded Corresponding Asset		27	30
US Plan | Defined Benefit Pension Plans | Other current assets
Amounts recognized in the consolidated balance sheets
Annuitized Unfunded Corresponding Asset		3	3
US Plan | Defined Benefit Pension Plans | Other assets
Amounts recognized in the consolidated balance sheets
Annuitized Unfunded Corresponding Asset		24	27
Foreign | Defined Benefit Pension Plans
Amounts recognized in the consolidated balance sheets
Long-term pension assets		437	559
Defined benefit pension liabilities		(271)	(276)
Net amount recognized		$ 166	$ 283
U.K. | Defined Benefit Pension Plans
Retirement Benefits, Description [Abstract]
Increase to pension obligation due to U.K. High Court judgment	$ 52