Equity Activity - AOCI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income/(Loss) (net of tax)
Balance at the beginning of the period	$ 2,686	$ 3,420
Other comprehensive income/(loss), net of tax	(173)	6
Balance at the end of the period	2,445	3,164
Accumulated Other Comprehensive Income/(Loss)
Accumulated Other Comprehensive Income/(Loss) (net of tax)
Balance at the beginning of the period	(31)	(33)
Other comprehensive income before reclassification	(174)	6
Amount reclassified from accumulated other comprehensive income	1	0
Other comprehensive income/(loss), net of tax	(173)	6
Balance at the end of the period	(204)	(27)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income/(Loss) (net of tax)
Balance at the beginning of the period	(12)	(23)
Other comprehensive income before reclassification	(174)	6
Other comprehensive income/(loss), net of tax	(174)	6
Balance at the end of the period	(186)	(17)
Net Change Retirement-Related Benefit Plans
Accumulated Other Comprehensive Income/(Loss) (net of tax)
Balance at the beginning of the period	(19)	(10)
Other comprehensive income before reclassification	0	0
Amount reclassified from accumulated other comprehensive income	1	0
Other comprehensive income/(loss), net of tax	1	0
Balance at the end of the period	$ (18)	$ (10)