Pension and Postretirement Benefit Plans - Pension Asset Fair Value Level 3 (Details) - International Qualified and Non-qualified Pension Benefits - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Benefit Plan Information | ||
| Foreign currency exchange | $ (444) | $ (498) |
| Level 3 | ||
| Benefit Plan Information | ||
| Foreign currency exchange | (9) | (36) |
| Defined benefit plan increases related to net purchases and unrealized gains losses | $ 8 | $ 16 |