Schedule of Senior Unsecured Notes Redemption Prices (Detail) - 4.500% Senior Unsecured Notes Due 2026 [Member] |
12 Months Ended |
---|---|
Mar. 31, 2018 | |
2021 [Member] | |
Debt Instrument Redemption [Line Items] | |
Redemption price, percentage | 102.25% |
2022 [Member] | |
Debt Instrument Redemption [Line Items] | |
Redemption price, percentage | 101.50% |
2023 [Member] | |
Debt Instrument Redemption [Line Items] | |
Redemption price, percentage | 100.75% |
2024 and Thereafter [Member] | |
Debt Instrument Redemption [Line Items] | |
Redemption price, percentage | 100.00% |