Intangible Assets - Schedule of Intangible Assets by Class (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 21,001	$ 21,036
Accumulated Amortization	4,365	3,394
Net Book Value	16,636	17,642
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,821	16,187
Accumulated Amortization	2,924	2,145
Net Book Value	12,897	14,042
Acquired software and technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,543	2,607
Accumulated Amortization	723	639
Net Book Value	1,820	1,968
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	616	620
Accumulated Amortization	138	105
Net Book Value	478	515
Capitalized software development costs
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,104	942
Accumulated Amortization	363	332
Net Book Value	741	610
Purchased software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	917	680
Accumulated Amortization	217	173
Net Book Value	$ 700	$ 507