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Fair Value Measurements (Financial Instruments' Carrying Amounts and Fair Values) (Parenthetical) (Detail) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2020 | Dec. 31, 2019
Fair Value Disclosures [Abstract] |  |
Valuation of certain fair value hedges associated with fixed rate debt | $ 3 | $ 4
Supplemental line of credit facility borrowings expiration period | 364 days |

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- References No definition available. + Details
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- Definition Fair value of all derivatives designated as interest rate fair value hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958 + Details
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