Financing Arrangement (Senior Notes) (Details) - USD ($)
$ in Millions |
1 Months Ended |
6 Months Ended |
|
|
Feb. 29, 2016 |
Sep. 30, 2016 |
Mar. 31, 2016 |
Feb. 24, 2016 |
| Debt Instrument [Line Items] |
|
|
|
|
| Senior Notes, Noncurrent |
|
$ 990
|
$ 989
|
|
| Proceeds from Issuance of Senior Long-term Debt |
$ 989
|
|
|
|
| 2021 Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Effective interest rate |
|
|
|
3.94%
|
| Debt Instrument, Convertible, Remaining Discount Amortization Period |
|
4 years 5 months
|
|
|
| Long-term Debt |
|
|
|
$ 600
|
| Debt Instrument, Interest Rate, Stated Percentage |
|
|
|
3.70%
|
| Debt Instrument, Maturity Date |
Mar. 01, 2021
|
|
|
|
| 2026 Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Effective interest rate |
|
|
|
4.97%
|
| Debt Instrument, Convertible, Remaining Discount Amortization Period |
|
9 years 5 months
|
|
|
| Long-term Debt |
|
|
|
$ 400
|
| Debt Instrument, Interest Rate, Stated Percentage |
|
|
|
4.80%
|
| Debt Instrument, Maturity Date |
Mar. 01, 2026
|
|
|
|
| Senior Notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt Instrument, Issuance Date |
Feb. 24, 2016
|
|
|
|
| Long-term Debt |
|
|
|
$ 1,000
|
| Debt Instrument, Unamortized Discount (Premium), Net |
|
$ (2)
|
(2)
|
(2)
|
| Debt Issuance Costs, Noncurrent, Net |
|
(8)
|
(9)
|
$ (9)
|
| Debt Instrument, Fair Value Disclosure |
|
$ 1,082
|
$ 1,039
|
|
| Senior Notes, Frequency of Periodic Payment |
semiannually
|
|
|
|
| Debt Instrument, Redemption Price, Percentage |
|
100.00%
|
|
|
| Change of control repurchase event |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Debt Instrument, Redemption Price, Percentage |
|
101.00%
|
|
|