Restructuring, Impairment, and Other Corporate Matters (Restructuring and Other Corporate Matters) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 134	$ 0	$ 336	$ 128
Merger-related costs	10	0	41	0
Other corporate matters	14	7	14	57
Restructuring and other corporate matters	158	7	391	185
Impairment charges	25	0		0
Depreciation of abandoned technology	0	0	12	0
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	128	0	304	98
Exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 6	$ 0	$ 32	$ 30