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Basis of Presentation - Adoption of New Accounting Standards - Narrative (Details) $ in Millions | Jan. 01, 2018 USD ($)
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New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Cumulative effect of new accounting principle in period of adoption | $ (8)
Accounting Standards Update 2014-09 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Cumulative effect of new accounting principle in period of adoption | 5
Accounting Standards Update 2016-01 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Cumulative effect of new accounting principle in period of adoption | 8
Accounting Standards Update 2016-16 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Cumulative effect of new accounting principle in period of adoption | 54
Accounting Standards Update 2017-12 | New Accounting Pronouncement, Early Adoption, Effect |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Cumulative effect of new accounting principle in period of adoption | $ (11)

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