Fair Value Measurements (Narrative) (Details) $ in Millions	Sep. 30, 2020 USD ($)
Fair Value Disclosures [Abstract]
Finance lease, liability, noncurrent	$ 45
Debt excluding short-term borrowings and capital lease obligations, carrying value	$ 29,293

Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

Name:	us-gaap_FinanceLeaseLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant