Reclassifications From Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassifications from accumulated other comprehensive (loss) income
Other income (expense), net	$ 45	$ 46		$ 88	$ 90
Interest expense	41	38		80	79
Tax (benefit)	95	88		136	127
Reclassifications, after tax	(252)	(224)		(379)	(385)
Reclassification of disproportionate tax effects			$ 0
Accounting Standards Update 2018-02
Reclassifications from accumulated other comprehensive (loss) income
Reclassification of disproportionate tax effects					59
Reclassification out of Accumulated Other Comprehensive Income | Actuarial losses, net
Reclassifications from accumulated other comprehensive (loss) income
Other income (expense), net	6	5		11	10
Tax (benefit)	(2)	(2)		(3)	(2)
Reclassifications, after tax	4	3		8	8
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Interest rate swaps
Reclassifications from accumulated other comprehensive (loss) income
Interest expense	1			1
Tax (benefit)	0			0
Reclassifications, after tax	$ 1			$ 1
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Interest rate swaps
Reclassifications from accumulated other comprehensive (loss) income
Interest expense		1			1
Tax (benefit)		0			0
Reclassifications, after tax		$ 1			$ 1