Expiration Years of Minimum Alternate Tax Credit (Detail) (Minimum Alternate Tax (MAT), USD $) In Millions, unless otherwise specified	Jun. 30, 2014
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	$ 23.77
2017-18
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	0.22
2018-19
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	0.30
2019-20
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	1.08
2020-21
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	4.77
2021-22
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	0.88
2022-23
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	6.60
2023-24
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	7.45
2024-25
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	$ 2.47