Employee Benefit Plans (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2020
Components of Net Periodic Benefit Costs:
Defined benefit plans	$ 13,000,000	$ 32,000,000	$ 37,000,000	$ 68,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	(98,000,000)	21,000,000	(86,000,000)	36,000,000
Amortization of net actuarial (loss) gain	(33,000,000)	(44,000,000)	(73,000,000)	(89,000,000)
Amortization of net prior service credit	20,000,000	21,000,000	39,000,000	40,000,000
Pension Plan
Contributions [Abstract]
Defined benefit plan, contributions by employer			64,000,000	70,000,000	$ 141,000,000
Pension Plan | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions						$ 135,000,000
Pension Plan | U.S.
Components of Net Periodic Benefit Costs:
Service cost	0	1,000,000	1,000,000	1,000,000
Interest cost	21,000,000	28,000,000	44,000,000	58,000,000
Expected return on plan assets	(26,000,000)	(25,000,000)	(52,000,000)	(51,000,000)
Recognized net actuarial loss (gain)	7,000,000	6,000,000	14,000,000	11,000,000
Amortization of prior service credit	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Recognized settlement loss	13,000,000	27,000,000	32,000,000	58,000,000
Recognized curtailment gain			0	0
Defined benefit plans	14,000,000	36,000,000	38,000,000	76,000,000
Defined contribution plans	6,000,000	5,000,000	11,000,000	13,000,000
Net Periodic Benefit Cost (Credit)	20,000,000	41,000,000	49,000,000	89,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	(92,000,000)	21,000,000	(80,000,000)	36,000,000
Amortization of net actuarial (loss) gain	(20,000,000)	(33,000,000)	(46,000,000)	(69,000,000)
Amortization of net prior service credit	1,000,000	1,000,000	1,000,000	1,000,000
Total Recognized in Other Comprehensive (Loss) Income	(111,000,000)	(11,000,000)	(125,000,000)	(32,000,000)
Total Recognized in Net Periodic Benefit (Credit) Cost and Other Comprehensive Income (Loss)	(91,000,000)	30,000,000	(76,000,000)	57,000,000
Contributions [Abstract]
Defined benefit plan, contributions by employer			12,000,000	13,000,000	26,000,000
Pension Plan | U.S. | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions						25,000,000
Pension Plan | U.S. | Qualified Plan
Contributions [Abstract]
Mandatory future contributions	0		0
Pension Plan | Non-U.S.
Components of Net Periodic Benefit Costs:
Service cost	5,000,000	5,000,000	10,000,000	12,000,000
Interest cost	26,000,000	38,000,000	55,000,000	77,000,000
Expected return on plan assets	(46,000,000)	(58,000,000)	(93,000,000)	(118,000,000)
Recognized net actuarial loss (gain)	14,000,000	12,000,000	28,000,000	22,000,000
Amortization of prior service credit	0	(1,000,000)	0	(1,000,000)
Recognized settlement loss	0	0	0	0
Recognized curtailment gain			(1,000,000)	0
Defined benefit plans	(1,000,000)	(4,000,000)	(1,000,000)	(8,000,000)
Defined contribution plans	5,000,000	6,000,000	10,000,000	12,000,000
Net Periodic Benefit Cost (Credit)	4,000,000	2,000,000	9,000,000	4,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	0	0	0	0
Amortization of net actuarial (loss) gain	(14,000,000)	(12,000,000)	(28,000,000)	(22,000,000)
Amortization of net prior service credit	0	1,000,000	0	1,000,000
Total Recognized in Other Comprehensive (Loss) Income	(14,000,000)	(11,000,000)	(28,000,000)	(21,000,000)
Total Recognized in Net Periodic Benefit (Credit) Cost and Other Comprehensive Income (Loss)	(10,000,000)	(9,000,000)	(19,000,000)	(17,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer			52,000,000	57,000,000	115,000,000
Pension Plan | Non-U.S. | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions						110,000,000
Retiree Health
Components of Net Periodic Benefit Costs:
Service cost	0	1,000,000	1,000,000	1,000,000
Interest cost	4,000,000	4,000,000	6,000,000	8,000,000
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss (gain)	(1,000,000)	(1,000,000)	(1,000,000)	(2,000,000)
Amortization of prior service credit	(19,000,000)	(19,000,000)	(38,000,000)	(38,000,000)
Recognized settlement loss	0	0	0	0
Recognized curtailment gain			0	0
Defined benefit plans	(16,000,000)	(15,000,000)	(32,000,000)	(31,000,000)
Net Periodic Benefit Cost (Credit)	(16,000,000)	(15,000,000)	(32,000,000)	(31,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	(6,000,000)	0	(6,000,000)	0
Amortization of net actuarial (loss) gain	1,000,000	1,000,000	1,000,000	2,000,000
Amortization of net prior service credit	19,000,000	19,000,000	38,000,000	38,000,000
Total Recognized in Other Comprehensive (Loss) Income	14,000,000	20,000,000	33,000,000	40,000,000
Total Recognized in Net Periodic Benefit (Credit) Cost and Other Comprehensive Income (Loss)	$ (2,000,000)	$ 5,000,000	1,000,000	9,000,000
Contributions [Abstract]
Defined benefit plan, contributions by employer			$ 9,000,000	$ 16,000,000	$ 30,000,000
Retiree Health | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions						$ 35,000,000