The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

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

Goodwill and Intangible Assets, Net - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) item product	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Goodwill and Intangible Assets [Line Items]
Amortization expense associated with definite-lived intangible assets	$ 14	$ 15
Net Carrying Value	$ 498		$ 512
Pharma Segment \| Vivus
Goodwill and Intangible Assets [Line Items]
Number of approved therapies \| item	2
Number of product candidate in active clinical development \| product	1
Developed Technology
Goodwill and Intangible Assets [Line Items]
Net Carrying Value	$ 213		$ 220