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Share-based compensation - Additional Information (Detail) (USD $)
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3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
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Mar. 31, 2012
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Mar. 31, 2011
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Mar. 31, 2012
Year
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Mar. 31, 2011
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Weighted average fair value of options granted during the period | $ 12.48 | $ 14.14 | $ 15.02 | |
| Total intrinsic value of options exercised | $ 236,000 | $ 270,000 | $ 1,800,000 | |
| Total fair value of options vested | 698,000 | 677,000 | ||
| Stock-based compensation cost | 241,000 | 87,000 | 1,389,000 | 937,000 |
| Total unrecognized compensation cost related to non-vested stock options | $ 2,400,000 | $ 2,400,000 | ||
| Weighted average period over which the compensation cost is expected to be recognized | 1.3 | |||