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Shareholders' Equity - Additional information (Detail) (USD $)
Share data in Millions, except Per Share data, unless otherwise specified |
1 Months Ended | 3 Months Ended | 9 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Jul. 31, 2012
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Apr. 30, 2012
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Feb. 29, 2012
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Sep. 30, 2012
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Jun. 30, 2012
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Mar. 31, 2012
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Sep. 30, 2011
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Sep. 30, 2012
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Sep. 30, 2011
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Aug. 30, 2012
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Jul. 30, 2012
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May 30, 2012
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May 02, 2012
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Mar. 22, 2012
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| Cash dividends per common share | $ 0.30 | $ 0.30 | $ 0.30 | |||||||||||
| Aggregate amount of cash dividend paid | $ 32,400,000 | $ 35,100,000 | $ 35,200,000 | |||||||||||
| Dividends and dividend equivalents | 32,400,000 | 23,500,000 | 102,687,000 | 62,177,000 | ||||||||||
| Share repurchase program capacity authorization | 1,000,000,000 | 1,000,000,000 | ||||||||||||
| Share repurchase program, remaining authorized capacity | 1,000,000,000 | 1,000,000,000 | 427,900,000 | |||||||||||
| Repurchase of common stock share | 3.9 | 3.9 | 5.3 | 0.7 | ||||||||||
| Average cost per share of share repurchased | $ 46.37 | $ 46.37 | $ 67.24 | |||||||||||
| Share repurchased through open market purchases, Aggregate cost | $ 181,900,000 | $ 246,000,000 | $ 50,000,000 | |||||||||||