Intangible Assets - Schedule of Intangible Assets by Class (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,519	$ 4,424
Accumulated Amortization	2,417	2,281
Net Book Value	2,102	2,143
Customer related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,642	2,642
Accumulated Amortization	1,365	1,294
Net Book Value	1,277	1,348
Acquired software and technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	591	591
Accumulated Amortization	505	490
Net Book Value	86	101
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	120	120
Accumulated Amortization	74	71
Net Book Value	46	49
Capitalized software development costs
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	893	810
Accumulated Amortization	353	314
Net Book Value	540	496
Purchased software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	273	261
Accumulated Amortization	120	112
Net Book Value	$ 153	$ 149