Employee Benefit Plans (Details) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2019
Components of Net Periodic Benefit Costs:
Defined benefit plans		$ 32,000,000	$ 26,000,000	$ 68,000,000	$ 53,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss		21,000,000	22,000,000	36,000,000	(36,000,000)
Amortization of net actuarial (loss) benefit	[1]	(44,000,000)	(47,000,000)	(89,000,000)	(93,000,000)
Amortization of prior service credit	[1]	21,000,000	3,000,000	40,000,000	5,000,000
Pension Plan
Contributions [Abstract]
Defined benefit plan, contributions by employer				70,000,000	75,000,000	$ 144,000,000
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		1,000,000	0	1,000,000	1,000,000
Interest cost		28,000,000	34,000,000	58,000,000	67,000,000
Expected return on plan assets		(25,000,000)	(36,000,000)	(51,000,000)	(70,000,000)
Recognized net actuarial loss (gain)		6,000,000	6,000,000	11,000,000	12,000,000
Amortization of prior service credit		(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Recognized settlement loss		27,000,000	26,000,000	58,000,000	51,000,000
Defined benefit plans		36,000,000	29,000,000	76,000,000	60,000,000
Defined contribution plans	[2]	5,000,000	10,000,000	13,000,000	19,000,000
Net Periodic Benefit Cost (Credit)		41,000,000	39,000,000	89,000,000	79,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	[3]	21,000,000	12,000,000	36,000,000	(46,000,000)
Amortization of net actuarial (loss) benefit		(33,000,000)	(32,000,000)	(69,000,000)	(63,000,000)
Amortization of prior service credit		1,000,000	1,000,000	1,000,000	1,000,000
Total Recognized in Other Comprehensive Income	[4]	(11,000,000)	(19,000,000)	(32,000,000)	(108,000,000)
Total Recognized in Net Periodic Benefit Cost and Other Comprehensive Income (Loss)		30,000,000	20,000,000	57,000,000	(29,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer				13,000,000	14,000,000	27,000,000
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]
Defined benefit plan, contributions by employer				0
Pension Plan | Non-U.S.
Components of Net Periodic Benefit Costs:
Service cost		5,000,000	7,000,000	12,000,000	13,000,000
Interest cost		38,000,000	38,000,000	77,000,000	77,000,000
Expected return on plan assets		(58,000,000)	(62,000,000)	(118,000,000)	(125,000,000)
Recognized net actuarial loss (gain)		12,000,000	15,000,000	22,000,000	30,000,000
Amortization of prior service credit		(1,000,000)	(1,000,000)	(1,000,000)	(2,000,000)
Recognized settlement loss		0	0	0	0
Defined benefit plans		(4,000,000)	(3,000,000)	(8,000,000)	(7,000,000)
Defined contribution plans	[2]	6,000,000	7,000,000	12,000,000	14,000,000
Net Periodic Benefit Cost (Credit)		2,000,000	4,000,000	4,000,000	7,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	[3]	0	0	0	0
Amortization of net actuarial (loss) benefit		(12,000,000)	(15,000,000)	(22,000,000)	(30,000,000)
Amortization of prior service credit		1,000,000	1,000,000	1,000,000	2,000,000
Total Recognized in Other Comprehensive Income	[4]	(11,000,000)	(14,000,000)	(21,000,000)	(28,000,000)
Total Recognized in Net Periodic Benefit Cost and Other Comprehensive Income (Loss)		(9,000,000)	(10,000,000)	(17,000,000)	(21,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer				57,000,000	61,000,000	117,000,000
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		1,000,000	1,000,000	1,000,000	2,000,000
Interest cost		4,000,000	7,000,000	8,000,000	13,000,000
Expected return on plan assets		0	0	0	0
Recognized net actuarial loss (gain)		(1,000,000)	0	(2,000,000)	0
Amortization of prior service credit		(19,000,000)	(1,000,000)	(38,000,000)	(2,000,000)
Recognized settlement loss		0	0	0	0
Defined benefit plans		(15,000,000)	7,000,000	(31,000,000)	13,000,000
Net Periodic Benefit Cost (Credit)		(15,000,000)	7,000,000	(31,000,000)	13,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss):
Net actuarial loss	[3]	0	10,000,000	0	10,000,000
Amortization of net actuarial (loss) benefit		1,000,000	0	2,000,000	0
Amortization of prior service credit		19,000,000	1,000,000	38,000,000	2,000,000
Total Recognized in Other Comprehensive Income	[4]	20,000,000	11,000,000	40,000,000	12,000,000
Total Recognized in Net Periodic Benefit Cost and Other Comprehensive Income (Loss)		$ 5,000,000	$ 18,000,000	9,000,000	25,000,000
Contributions [Abstract]
Defined benefit plan, contributions by employer				$ 16,000,000	$ 29,000,000	$ 57,000,000
Retiree Health | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions							$ 35,000,000

[1] Reclassified to Total Net Periodic Benefit Cost - refer to Note 16 - Employee Benefit Plans for additional information.

[2] Prior year amounts have been revised to reflect additional cost for previously excluded plans.

[3] The net actuarial loss (gain) for U.S. Plans primarily reflects (i) the remeasurement of our primary U.S. pension plans as a result of the payment of periodic settlements and (ii) adjustments for the actuarial valuation results based on January 1st plan census data.

[4] Amounts represent the pre-tax effect included within Other Comprehensive Income. Refer to Note 19 - Other Comprehensive Income (Loss) for related tax effects and the after-tax amounts.