Long-Term Debt and Revolving Credit Arrangements - Interest Expense (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
|
| Debt Disclosure [Abstract] | ||||
| Contractual interest coupon | $ 83 | $ 59 | $ 338 | $ 148 |
| Amortization of debt discount and issuance costs | 2 | 82 | 80 | 231 |
| 8% IRR payout | 0 | 16 | 26 | 45 |
| Total interest expense from long-term debt | $ 85 | $ 157 | $ 444 | $ 424 |