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Leases - Narrative (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Leases [Line Items] |  |
Cumulative effect of accounting changes |  | $ 195
Retained earnings |  |
Leases [Line Items] |  |
Cumulative effect of accounting changes |  | $ 165
ASC 842 | Retained earnings |  |
Leases [Line Items] |  |
Cumulative effect of accounting changes | $ 0 |

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- Definition [Line Items] for Leases [Table] + References No definition available. + Details
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- Definition Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption. + References No definition available. + Details
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- Details
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- Details
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