Postretirement Benefit Plans - Assumed Future Benefits Payments (Details) $ in Millions	Dec. 31, 2016 USD ($)
U.S. defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
2017 payment	$ 128
2018 payment	120
2019 payment	86
2020 payment	91
2021 payment	101
2022 - 2026 payment	450
U.S. retiree health care plan
Defined Benefit Plan Disclosure [Line Items]
2017 payment	32
2018 payment	32
2019 payment	33
2020 payment	33
2021 payment	32
2022 - 2026 payment	151
Non-U.S. defined benefit plan
Defined Benefit Plan Disclosure [Line Items]
2017 payment	82
2018 payment	84
2019 payment	87
2020 payment	89
2021 payment	91
2022 - 2026 payment	$ 489