Revenue Recognition - Narratives (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Allowance for credit losses, period increase (decrease)	$ 23
Allowance for credit losses	119	$ 119	$ 93
Provisions for doubtful receivables	69	$ 37
Contract assets	222		272
Deferred revenue	298		264
Contract with Customer, Liability, Noncurrent	$ 26		$ 26

Amount of allowance for credit loss on accounts receivable, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118955202&loc=SL82895884-210446

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in allowance for credit loss on accounts receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447

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- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
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Balance Type:	debit
Period Type:	instant

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable.

+ References

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- Definition

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

+ References

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- References

No definition available.

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