Contractual Maturities of Available for Sale Debt Securities (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Due within one year	$ 57,647
Due one to five years	143,966
Available-for-sale Securities, Fair Value Disclosure	$ 201,613

Amount of debt securities categorized neither as held-to-maturity nor trading.

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