New Accounting Standards (Details) $ in Millions	3 Months Ended
Dec. 31, 2018 USD ($)
ASU 2018-02
Recently Adopted Accounting Standards
Accumulated other comprehensive income (loss) to retained earnings stranded tax effects	$ 337

Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL116659650-108580

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration