Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Goodwill, Customer Relationships and Other Intangible Assets - Goodwill Impairment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill [Line Items]
Goodwill impairment	$ 6,506	$ 0
International and Global Accounts
Goodwill [Line Items]
Goodwill impairment	934
Enterprise
Goodwill [Line Items]
Goodwill impairment	1,471
Small and Medium Business
Goodwill [Line Items]
Goodwill impairment	896
Wholesale
Goodwill [Line Items]
Goodwill impairment	3,019
Consumer
Goodwill [Line Items]
Goodwill impairment	$ 186