Acquisitions (Preliminary Purchase Price Allocation) (Details) - USD ($) $ in Millions		Sep. 30, 2019	Sep. 06, 2019	Dec. 31, 2018	Sep. 06, 2016
Goodwill		$ 2,206		$ 1,956
Nomor [Member]
Current assets	[1]		$ 19
Property and equipment			6
Goodwill	[2]		152
Intangible intangible assets	[3]		94
Current liabilities	[4]		(21)
Long-term liabilities	[2]		(44)
Total purchase price			$ 207
Deferred tax liabilities, tax differences in intangible assets					$ 20

[1] Primarily trade receivables and cash

[2] Includes $20 million of deferred tax liabilities recognized as a result of tax basis differences in intangible assets.

[3] Primarily customer lists.

[4] Primarily advanced collections from customers