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Assumptions Used in Black-Scholes Option-Pricing Model (Detail)
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12 Months Ended | ||
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Jun. 30, 2012
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Jun. 30, 2011
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Jun. 30, 2010
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Dividend yield | 1.50% | 1.50% | 1.60% |
| Expected volatility, minimum | 22.00% | 22.00% | 22.00% |
| Expected volatility, maximum | 23.00% | 27.00% | 30.00% |
| Risk-free interest rates, minimum | 0.90% | 1.30% | 1.70% |
| Risk-free interest rates, maximum | 2.00% | 2.30% | 3.10% |
| Expected lives | 6 years | 5 years | 6 years |