Pension and Other Postemployment Benefits (Details 9) $ in Millions	Dec. 31, 2015 USD ($)
Pensions
Estimated Future Benefit Payments
2016	$ 484
2017	505
2018	522
2019	533
2020	551
2021-2025	2,946
OPEB \| Employer Subsidized Benefit
Estimated Future Benefit Payments
2016	54
2017	54
2018	54
2019	54
2020	54
2021-2025	259
OPEB \| Medicare Rx Reimbursement
Subsidy Receipts
2016	(3)
2017	(3)
2018	(3)
2019	(3)
2020	(3)
Years 2021-2025	$ (9)

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