Future Principal Payments For Senior Notes (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Debt Instrument [Line Items]
2015	$ 71,000
2016	60,000
2017	72,000
2018	131,000
2019	28,000
Thereafter	85,000
Total	$ 447,000

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year.

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