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Earnings per Share - Additional Information (Detail) $ / shares in Units, $ in Millions	Dec. 31, 2020 USD ($) $ / shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock price | $ / shares	$ 37.12
Senior Unsecured Convertible Bonds [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Debt instrument principal amount	$ 750
Expected excess amount over principal upon conversion	$ 605

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Expected excess amount over principal upon conversion.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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Price of a single share of a number of saleable stocks of a company.

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