Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Interest paid	$ 182	$ 155
Foreign and State
Income taxes paid	545	375
Domestic
Tax refunds	$ 2	$ 755

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

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The amount of cash received during the period as refunds for the overpayment of taxes.

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