Goodwill and Other Intangible Assets—Net - Reporting Unit Goodwill (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill	$ 791	$ 869
Reporting units 1-6
Goodwill [Line Items]
Fair value exceeds carrying value percentage	15.00%
Goodwill	$ 354
Reporting units 7-9
Goodwill [Line Items]
Fair value exceeds carrying value percentage	15.00%
Goodwill	$ 437

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant