Debt (First Lien Term Loans) (Details) - USD ($) $ in Millions |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Long-term Debt | $ 11,674 | $ 11,292 |
| First Lien Term Loan 2019 [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 794 | 795 |
| 2020 First Lien Term Loan [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 377 | 378 |
| 2022 First Lien Term Loan [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 1,568 | 1,571 |
| 2023 First Lien Term Loan [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term Debt | 532 | 533 |
| First Lien Term Loans [Member] | ||
| Debt Instrument [Line Items] | ||
| Long-term Debt | $ 3,271 | $ 3,277 |