Employee Benefit Plans (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2019
Components of Net Periodic Benefit Costs:
Defined benefit plans		$ 21,000,000	$ 36,000,000	$ 89,000,000	$ 89,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial loss (gain)		126,000,000	(53,000,000)	162,000,000	(89,000,000)
Amortization of net actuarial (loss) benefit	[1]	(34,000,000)	(53,000,000)	(123,000,000)	(146,000,000)
Amortization of prior service credit	[1]	19,000,000	2,000,000	59,000,000	7,000,000
Out-of-period adjustment			53,000,000		53,000,000
Pension Plan
Contributions [Abstract]
Defined benefit plan, contributions by employer				107,000,000	111,000,000	$ 144,000,000
Pension Plan | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions							$ 140,000,000
Pension Plan | U.S.
Components of Net Periodic Benefit Costs:
Service cost		1,000,000	1,000,000	2,000,000	2,000,000
Interest cost		25,000,000	35,000,000	83,000,000	102,000,000
Expected return on plan assets		(26,000,000)	(35,000,000)	(77,000,000)	(105,000,000)
Recognized net actuarial loss (gain)		7,000,000	5,000,000	18,000,000	17,000,000
Amortization of prior service credit		0	0	(1,000,000)	(1,000,000)
Recognized settlement loss		18,000,000	34,000,000	76,000,000	85,000,000
Defined benefit plans		25,000,000	40,000,000	101,000,000	100,000,000
Defined contribution plans	[2]	6,000,000	9,000,000	19,000,000	28,000,000
Net Periodic Benefit Cost (Credit)		31,000,000	49,000,000	120,000,000	128,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial loss (gain)	[3]	135,000,000	0	171,000,000	(46,000,000)
Amortization of net actuarial (loss) benefit		(25,000,000)	(39,000,000)	(94,000,000)	(102,000,000)
Amortization of prior service credit		0	0	1,000,000	1,000,000
Total Recognized in Other Comprehensive (Loss) Income	[4]	110,000,000	(39,000,000)	78,000,000	(147,000,000)
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income		141,000,000	10,000,000	198,000,000	(19,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer				19,000,000	20,000,000	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	6,000,000	17,000,000	19,000,000
Interest cost		37,000,000	37,000,000	114,000,000	114,000,000
Expected return on plan assets		(56,000,000)	(60,000,000)	(174,000,000)	(185,000,000)
Recognized net actuarial loss (gain)		10,000,000	14,000,000	32,000,000	44,000,000
Amortization of prior service credit		0	(1,000,000)	(1,000,000)	(3,000,000)
Recognized settlement loss		0	0	0	0
Defined benefit plans		(4,000,000)	(4,000,000)	(12,000,000)	(11,000,000)
Defined contribution plans	[2]	5,000,000	8,000,000	17,000,000	22,000,000
Net Periodic Benefit Cost (Credit)		1,000,000	4,000,000	5,000,000	11,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial loss (gain)	[3]	0	(53,000,000)	0	(53,000,000)
Amortization of net actuarial (loss) benefit		(10,000,000)	(14,000,000)	(32,000,000)	(44,000,000)
Amortization of prior service credit		0	1,000,000	1,000,000	3,000,000
Total Recognized in Other Comprehensive (Loss) Income	[4]	(10,000,000)	(66,000,000)	(31,000,000)	(94,000,000)
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income		(9,000,000)	(62,000,000)	(26,000,000)	(83,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer				88,000,000	91,000,000	117,000,000
Pension Plan | Non-U.S. | Forecast
Contributions [Abstract]
Defined benefit plan, expected future employer contributions							115,000,000
Retiree Health
Components of Net Periodic Benefit Costs:
Service cost		0	2,000,000	1,000,000	4,000,000
Interest cost		3,000,000	5,000,000	11,000,000	18,000,000
Expected return on plan assets		0	0	0	0
Recognized net actuarial loss (gain)		(1,000,000)	0	(3,000,000)	0
Amortization of prior service credit		(19,000,000)	(1,000,000)	(57,000,000)	(3,000,000)
Recognized settlement loss		0	0	0	0
Defined benefit plans		(17,000,000)	6,000,000	(48,000,000)	19,000,000
Net Periodic Benefit Cost (Credit)		(17,000,000)	6,000,000	(48,000,000)	19,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial loss (gain)	[3]	(9,000,000)	0	(9,000,000)	10,000,000
Amortization of net actuarial (loss) benefit		1,000,000	0	3,000,000	0
Amortization of prior service credit		19,000,000	1,000,000	57,000,000	3,000,000
Total Recognized in Other Comprehensive (Loss) Income	[4]	11,000,000	1,000,000	51,000,000	13,000,000
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income		$ (6,000,000)	$ 7,000,000	3,000,000	32,000,000
Contributions [Abstract]
Defined benefit plan, contributions by employer				$ 22,000,000	$ 42,000,000	$ 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. The non-U.S. plans net actuarial gain for 2018 reflects and out-of-period adjustment of $53 to correct an overstated benefit obligation for our U.K. Funded Pension Plan at December 31, 2017.

[4] Amounts represent the pre-tax effect included within Other Comprehensive (Loss) Income. Refer to Note 20 - Other Comprehensive (Loss) Income for related tax effects and the after-tax amounts.