Restructuring of Operations - Accrued Restructuring Costs and Activity (Details) $ in Millions |
3 Months Ended |
|---|---|
|
Mar. 31, 2018
USD ($)
| |
| Restructuring Reserve [Roll Forward] | |
| Beginning balance | $ 26 |
| Charges to restructuring | 1 |
| Cash payments | (5) |
| Ending balance | 22 |
| Employee Termination Benefits [Member] | |
| Restructuring Reserve [Roll Forward] | |
| Beginning balance | 21 |
| Charges to restructuring | |
| Cash payments | (4) |
| Ending balance | 17 |
| Exit Costs [Member] | |
| Restructuring Reserve [Roll Forward] | |
| Beginning balance | 5 |
| Charges to restructuring | 1 |
| Cash payments | (1) |
| Ending balance | $ 5 |