Long-Term Debt (Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
2017	$ 6
2018	2,013
2019	606
2020	806
2021	6
Thereafter	887
Total debt	$ 4,324	$ 4,561

Long term debt maturities and capital lease obligations repayments of principal after year five.

No definition available.

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Long term debt maturities and capital lease obligations repayments of principal in next twelve months.

No definition available.

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Long term debt maturities and capital lease obligations repayments of principal in year five.

No definition available.

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Long term debt maturities and capital lease obligations repayments of principal in year four.

No definition available.

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Long term debt maturities and capital lease obligations repayments of principal in year three.

No definition available.

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Long term debt maturities and capital lease obligations repayments of principal in year two.

No definition available.

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No definition available.

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Amount of long-term debt and capital lease obligations including current maturities.

No definition available.

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