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Segmented Information - Schedule of Segment Information for Reporting Segments and a Reconciliation for Adjusted EBIT to Consolidated Income Before Income Taxes (Parenthetical) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Segment Reporting [Abstract] |  |
Net Income from operations | $ 2,255 | $ 2,074
Add (deduct): |  |
Interest expense, net | 70 | 88
Other expense, net | 39 | 30
Income taxes | 744 | 706
Adjusted EBIT | $ 3,108 | $ 2,898

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