Cash Equivalents and Investments (Footnote) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Company owned life insurance (at contract value)	$ 17	$ 0
Short-term Investments \| Certificates of deposit and money market deposit accounts \| Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	1 month	1 month
Short-term Investments \| Certificates of deposit and money market deposit accounts \| Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	12 months	12 months
Other assets \| Certificates of deposit and money market deposit accounts \| Minimum
Cash and Cash Equivalents [Line Items]
Securities maturity period	13 months	13 months
Other assets \| Certificates of deposit and money market deposit accounts \| Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	23 months	18 months
Cash and cash equivalent \| Certificates of deposit and money market deposit accounts \| Maximum
Cash and Cash Equivalents [Line Items]
Securities maturity period	90 days

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.

No definition available.

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- Definition

Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6812-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Period of time between issuance and maturity of customer deposits, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher SEC
-Name Industry Guide
-Number 3
-Section V
-Paragraph D-E

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