Inventories (Schedule of Inventory) (Details) - USD ($) $ in Millions |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Inventory Disclosure [Abstract] | ||
| Finished products | $ 1,187 | $ 1,082 |
| Work in process | 179 | 160 |
| Raw materials | 446 | 413 |
| Supplies | 51 | 50 |
| Total | $ 1,863 | $ 1,705 |