Pension and Other Employee Benefits (Schedule of Funded Status Amounts Recognized on our Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Noncurrent assets	$ 174	$ 126
Current liabilities	(160)	(150)
Noncurrent liabilities	(7,687)	(6,111)
Net amount recognized on our balance sheets	(7,673)	(6,135)
PRB [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Noncurrent assets	0	0
Current liabilities	(18)	(18)
Noncurrent liabilities	(369)	(354)
Net amount recognized on our balance sheets	$ (387)	$ (372)

Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as noncurrent. Excludes other postretirement benefit plan.

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Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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