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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 | 12 Months Ended | ||||||||||
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Jul. 31, 2012
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Jun. 30, 2012
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May 31, 2012
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Mar. 31, 2012
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Jun. 30, 2011
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Sep. 30, 2010
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Jun. 30, 2010
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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Jul. 30, 2012
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May 03, 2010
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Apr. 30, 2009
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| Equity [Abstract] | |||||||||||||
| Common shares, shares outstanding | 106.9 | 115.8 | 117.8 | ||||||||||
| Preference shares authorized | 7.5 | ||||||||||||
| Preference shares par value | $ 0.002 | ||||||||||||
| Cash dividend per common share | $ 0.30 | $ 0.20 | $ 0.13 | $ 0.10 | |||||||||
| Increase in cash dividends per common share | $ 0.10 | $ 0.07 | $ 0.03 | ||||||||||
| Dividends paid | $ 135,091,000 | $ 85,489,000 | $ 53,740,000 | ||||||||||
| Share repurchase program capacity authorization | 1,000,000,000 | 1,000,000,000 | 300,000,000 | ||||||||||
| Previous expiration date of share repurchase program | Apr. 01, 2011 | ||||||||||||
| Revised expiration date of share repurchase program | Dec. 01, 2014 | ||||||||||||
| Repurchase of common stock | 427,900,000 | 556,727,000 | 321,639,000 | 160,008,000 | |||||||||
| Agreement expiration date | Jul. 27, 2012 | ||||||||||||
| Repurchase of common stock | 3.9 | 5.3 | 11.0 | 5.5 | 5.7 | ||||||||
| Share repurchase program, remaining authorized capacity | 950,000,000 | ||||||||||||
| Shares repurchased through open market purchases, aggregate cost | $ 527,800,000 | $ 298,800,000 | $ 150,100,000 | ||||||||||
| Average cost per share of shares repurchased | $ 47.78 | $ 54.27 | $ 26.13 | ||||||||||
| X | ||||||||||
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- Definition
Agreement expiration date. No definition available.
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- Definition
Average cost per share of share repurchased. No definition available.
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- Definition
Increase in common stock dividends per share cash paid. No definition available.
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- Definition
Previous expiration date of share repurchase program. No definition available.
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| X | ||||||||||
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- Definition
Revised expiration date of share repurchase program. No definition available.
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- Definition
Share repurchase program capacity authorization. No definition available.
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- Definition
Share repurchase program, remaining authorized capacity. No definition available.
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- Definition
Aggregate dividends paid during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The cash outflow to reacquire common stock during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Cash outflow in the form of ordinary dividends to common shareholders, generally out of earnings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Face amount or stated value per share of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer); generally not indicative of the fair market value per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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