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Recent Accounting Pronouncements (Narrative) (Detail) - USD ($) $ in Millions |  | 9 Months Ended |  |
--- | --- | --- | --- | ---
Jan. 01, 2020 | Sep. 30, 2019 | Dec. 31, 2019 | Jan. 01, 2019
Operating lease right of use asset |  |  | $ 21 | $ 23
Accounting Standards Update 2016-13 [Member] | Subsequent Event [Member] |  |  |  |
Cumulative-effect adjustment, net of tax | $ 42 |  |  |
Accounting Standards Update 2019-12 [Member] |  |  |  |
Intraperiod allocations |  | $ 29 |  |

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- Definition Amount of the cumulative effect on retained earnings net of related income tax effect. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794 + Details
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- Definition Amount of lessee's right to use underlying asset under operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
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