Pension Benefits Narrative (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2015 |
Dec. 31, 2014 |
|
| Compensation and Retirement Disclosure [Abstract] | ||
| Defined Benefit Pension Plan, Postemployment Benefit Period | 5 years | |
| Other Postretirement Benefits Payable | $ 3 | $ 3 |