Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Income Tax Contingency [Line Items] | ||||
| Income tax (expense) benefit | $ 4 | $ (28) | $ (17) | $ (32) |
| Effective Income Tax Rate, Continuing Operations | (1.00%) | 9.00% | 20.00% | 10.00% |
| Income Tax Uncertainties [Abstract] | ||||
| Unrecognized Tax Benefits | $ 58 | $ 58 | ||
| Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 18 | 18 | ||
| Unrecognized Tax Benefit Related to Deferred Tax Asset | 40 | 40 | ||
| Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued | 13 | 13 | ||
| Minimum [Member] | ||||
| Income Tax Contingency [Line Items] | ||||
| Decrease in Unrecognized Tax Benefits is Reasonably Possible | 0 | 0 | ||
| Maximum [Member] | ||||
| Income Tax Contingency [Line Items] | ||||
| Decrease in Unrecognized Tax Benefits is Reasonably Possible | $ 19 | $ 19 | ||