Debt - Long Term Debt (Phantom) (Detail) |
12 Months Ended | |
|---|---|---|
Mar. 31, 2017 |
Apr. 23, 2015 |
|
| Senior Unsecured 3.375% Convertible Notes Due 2038 | ||
| Debt Instrument [Line Items] | ||
| Interest rate of debt instrument | 3.375% | 3.375% |
| Maturity year | 2038 | |
| 2011 Credit Facility Due 2018 | ||
| Debt Instrument [Line Items] | ||
| Maturity year | 2018 |