Supplemental Financial Information - Allowance for Doubtful Accounts (Details) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Allowances for Doubtful Accounts and Product Returns
Balance at December 31, 2019	$ 228
Provisions/charges to income	88
Amounts charged off and other deductions	(35)
Balance at December 31, 2020	288
Impact of adoption of new accounting standards \| ASU 2016-13
Allowances for Doubtful Accounts and Product Returns
Balance at December 31, 2020	$ 7

Amount of allowance for credit loss on accounts receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

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- Definition

Amount of direct write-downs of accounts receivable charged against the allowance.

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- Definition

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- Definition

Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

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