Redemption Price of Notes Plus Accrued and Unpaid Interest Thereon to Redemption Date (Detail) (5% Senior Notes)	Jun. 30, 2012
Redemption 2016
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	102.50%
Redemption 2017
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	101.25%
Redemption 2018 and Thereafter
Debt Instrument [Line Items]
Redemption price as percentage of principal amount	100.00%