Stock Option Activity (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Option Shares
Outstanding at beginning of year	2.0	1.9	2.1
Granted	0.6	0.7	0.4
Canceled or expired	(0.3)	(0.6)	(0.6)
Outstanding at end of year	2.3	2.0	1.9
Exercisable at end of year	1.3	1.0	1.2
Weighted Average Exercise Price
Outstanding at beginning of year	$ 10.16	$ 12.61	$ 13.60
Granted	$ 5.52	$ 6.50	$ 8.93
Canceled or expired	$ 9.88	$ 14.02	$ 13.47
Outstanding at end of year	$ 8.93	$ 10.16	$ 12.61
Exercisable at end of year	$ 11.22	$ 13.12	$ 14.84

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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

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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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