Stock Option Information (Detail) (Employee Stock Option, USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
Sep. 30, 2012
Employee Stock Option
Shares
Outstanding at beginning of year	9,357
Granted	536
Exercised	(400)
Forfeited or expired	(1,200)
Outstanding at end of year	8,293
Weighted-average exercise price
Outstanding at beginning of year	$ 36.71
Granted	$ 35.63
Exercised	$ 30.82
Forfeited or expired	$ 35.62
Outstanding at end of year	$ 37.09

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Net number of share options (or share units) granted during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees can acquire the shares reserved for issuance on stock options awarded.

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Number of share options (or share units) exercised during the current period.

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