Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total
Beginning balance	$ 4,844
Comprehensive (loss) income before reclassifications	1	$ (83)	$ (198)
Income taxes associated with comprehensive (loss) income before reclassifications	61	0	19
Reclassification from accumulated other comprehensive (loss) income	17	38	12
Income taxes reclassified into net earnings	(397)	(468)	(211)
Ending balance	6,724	4,844
Gain (loss) reclassified from AOCI to income
Total
Income taxes reclassified into net earnings	(3)	(8)	(3)
Accumulated other comprehensive income (loss)
Total
Beginning balance	(727)	(674)	(490)
Ending balance	(651)	(727)	(674)
Accumulated other comprehensive income (loss) | Cumulative Effect, Period of Adoption, Adjustment
Total
Beginning balance			(14)
Foreign currency translation adjustments
Total
Beginning balance	(497)	(442)	(294)
Comprehensive (loss) income before reclassifications	133	(51)	(153)
Income taxes associated with comprehensive (loss) income before reclassifications	43	(4)	5
Reclassification from accumulated other comprehensive (loss) income	0	0	0
Ending balance	(321)	(497)	(442)
Foreign currency translation adjustments | Gain (loss) reclassified from AOCI to income
Total
Income taxes reclassified into net earnings	0	0	0
Foreign currency translation adjustments | Cumulative Effect, Period of Adoption, Adjustment
Total
Beginning balance			0
Hedge instruments
Total
Beginning balance	0	0	(1)
Comprehensive (loss) income before reclassifications	(1)	(1)	(2)
Income taxes associated with comprehensive (loss) income before reclassifications	0	0	0
Reclassification from accumulated other comprehensive (loss) income	1	1	4
Ending balance	0	0	0
Hedge instruments | Gain (loss) reclassified from AOCI to income
Total
Income taxes reclassified into net earnings	0	0	(1)
Hedge instruments | Cumulative Effect, Period of Adoption, Adjustment
Total
Beginning balance			0
Defined benefit postretirement plans
Total
Beginning balance	(230)	(234)	(198)
Comprehensive (loss) income before reclassifications	(131)	(29)	(42)
Income taxes associated with comprehensive (loss) income before reclassifications	18	4	14
Reclassification from accumulated other comprehensive (loss) income	16	37	8
Ending balance	(330)	(230)	(234)
Defined benefit postretirement plans | Gain (loss) reclassified from AOCI to income
Total
Income taxes reclassified into net earnings	(3)	(8)	(2)
Defined benefit postretirement plans | Cumulative Effect, Period of Adoption, Adjustment
Total
Beginning balance			(14)
Other
Total
Beginning balance	0	2	3
Comprehensive (loss) income before reclassifications	0	(2)	(1)
Income taxes associated with comprehensive (loss) income before reclassifications	0	0	0
Reclassification from accumulated other comprehensive (loss) income	0	0	0
Ending balance	0	0	2
Other | Gain (loss) reclassified from AOCI to income
Total
Income taxes reclassified into net earnings	$ 0	$ 0	0
Other | Cumulative Effect, Period of Adoption, Adjustment
Total
Beginning balance			$ 0