Comparison of Key Financial Covenants and Current Compliance (Detail)	Jun. 30, 2013
Financing Activities and Borrowing Arrangements [Line Items]
Permitted leverage ratio, maximum	0.92
Minimum interest coverage ratio	17.19%
Covenant Requirement
Financing Activities and Borrowing Arrangements [Line Items]
Permitted leverage ratio, maximum	3.00
Minimum interest coverage ratio	4.00%