Consolidated Statements of Cash Flows (Parenthetical 1) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Consolidated Statements of Cash Flows [Abstract]
Sale of premises and equipment	$ 1	$ 1

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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