Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit costs	$ 2			$ (8)			$ 9	$ (11)
Income before income taxes	175			357			395	1,021
Net interest and other	(64)			(58)			(177)	(168)
Foreign currency translation adjustment related to sale of U.K pension plan	30			0			30	0
Income tax impact	(7)			0			(7)	0
Net income	165	$ 161	$ 174	254	$ 96	$ 356	500	706
Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Divestiture of U.K. pension plan	83			0			83	0
Amortization of prior service credit | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit costs	6			4			19	13
Amortization of actuarial loss | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit costs	(3)			(3)			(7)	(10)
Net settlement loss | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net periodic benefit costs	0			(10)			(2)	(16)
Postretirement and postemployment plans | Reclassification out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	3			(9)			10	(13)
Net interest and other	0			(4)			0	(4)
Income tax impact	46			0			46	0
Net income	$ 70			$ (13)			$ 77	$ (17)