Goodwill and Intangible Assets - Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,871		$ 4,816
Accumulated Amortization	(4,033)		(3,922)
Net Carrying Amount	838		894
Amortization expense	$ 111	$ 156
Acquired users
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Lives (in years)	1 year 6 months
Gross Carrying Amount	$ 2,056		2,056
Accumulated Amortization	(1,622)		(1,550)
Net Carrying Amount	$ 434		506
Acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Lives (in years)	2 years 6 months
Gross Carrying Amount	$ 1,213		1,158
Accumulated Amortization	(1,007)		(986)
Net Carrying Amount	$ 206		172
Acquired patents
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Lives (in years)	4 years 4 months 24 days
Gross Carrying Amount	$ 805		805
Accumulated Amortization	(638)		(625)
Net Carrying Amount	$ 167		180
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Lives (in years)	1 year 9 months 18 days
Gross Carrying Amount	$ 635		635
Accumulated Amortization	(609)		(604)
Net Carrying Amount	$ 26		31
Other
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Lives (in years)	3 years 1 month 6 days
Gross Carrying Amount	$ 162		162
Accumulated Amortization	(157)		(157)
Net Carrying Amount	$ 5		$ 5