Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amounts Recognized in the Consolidated Balance Sheets:
Pension and other benefit liabilities	$ (1,707)	$ (1,482)
Post-retirement medical benefits	(352)	(350)
Pension Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation - ending	10,090
Change in Plan Assets:
Fair value of plan assets -beginning	8,087
Employer contributions	141
Fair value of plan assets - ending	8,878	8,087
Net Funded Status	(1,212)
Other Postretirement Benefits Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation - beginning	385	723
Service cost	2	4	$ 5
Interest cost	15	23	28
Plan participants' contributions	10	3
Actuarial loss (gain)	8	(63)
Currency exchange rate changes	5	(11)
Plan Amendments/Curtailments	0	(234)
Benefits paid/settlements	(40)	(60)
Other	0	0
Benefit obligation - ending	385	385	723
Change in Plan Assets:
Fair value of plan assets -beginning	0	0
Actual return on plan assets	0	0
Employer contributions	30	57
Plan participants' contributions	10	3
Currency exchange rate changes	0	0
Benefits paid/settlements	(40)	(60)
Other	0	0
Fair value of plan assets - ending	0	0	0
Net Funded Status	(385)	(385)
Amounts Recognized in the Consolidated Balance Sheets:
Other long-term assets	0	0
Accrued compensation and benefit costs	(33)	(35)
Pension and other benefit liabilities	0	0
Post-retirement medical benefits	(352)	(350)
Net Amounts Recognized	(385)	(385)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss (gain)	(29)	(42)
Prior service (credit) cost	(164)	(240)
Total Pre-tax loss (gain)	(193)	(282)
United States | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation - beginning	3,234	4,180
Service cost	2	2	2
Interest cost	218	63	226
Plan participants' contributions	0	0
Actuarial loss (gain)	564	(288)
Currency exchange rate changes	0	0
Plan Amendments/Curtailments	0	0
Benefits paid/settlements	(420)	(723)
Other	0	0
Benefit obligation - ending	3,598	3,234	4,180
Change in Plan Assets:
Fair value of plan assets -beginning	2,358	3,224
Actual return on plan assets	529	(170)
Employer contributions	26	27
Plan participants' contributions	0	0
Currency exchange rate changes	0	0
Benefits paid/settlements	(420)	(723)
Other	0	0
Fair value of plan assets - ending	2,493	2,358	3,224
Net Funded Status	(1,105)	(876)
Amounts Recognized in the Consolidated Balance Sheets:
Other long-term assets	0	0
Accrued compensation and benefit costs	(25)	(25)
Pension and other benefit liabilities	(1,080)	(851)
Post-retirement medical benefits	0	0
Net Amounts Recognized	(1,105)	(876)
Accumulated Benefit Obligation	3,598	3,234
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss (gain)	1,059	933
Prior service (credit) cost	(3)	(5)
Total Pre-tax loss (gain)	1,056	928
Foreign Plan | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation - beginning	6,007	6,703
Service cost	22	27	29
Interest cost	153	149	158
Plan participants' contributions	3	4
Actuarial loss (gain)	472	(293)
Currency exchange rate changes	114	(339)
Plan Amendments/Curtailments	(2)	41
Benefits paid/settlements	(270)	(281)
Other	(7)	(4)
Benefit obligation - ending	6,492	6,007	6,703
Change in Plan Assets:
Fair value of plan assets -beginning	5,729	6,308
Actual return on plan assets	680	(85)
Employer contributions	115	117
Plan participants' contributions	3	4
Currency exchange rate changes	135	(329)
Benefits paid/settlements	(270)	(281)
Other	(7)	(5)
Fair value of plan assets - ending	6,385	5,729	$ 6,308
Net Funded Status	(107)	(278)
Amounts Recognized in the Consolidated Balance Sheets:
Other long-term assets	451	281
Accrued compensation and benefit costs	(22)	(24)
Pension and other benefit liabilities	(536)	(535)
Post-retirement medical benefits	0	0
Net Amounts Recognized	(107)	(278)
Accumulated Benefit Obligation	6,326	5,847
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss (gain)	1,462	1,457
Prior service (credit) cost	22	19
Total Pre-tax loss (gain)	$ 1,484	$ 1,476