Employee service share based compensation incremental tax benefit to be realized from exercise of stock awards.

No definition available.

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- Definition

Fair value of restricted stock units which contain four year vesting periods.

+ References

No definition available.

+ Details

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- Definition

Fair value of restricted stock units which contain three-year vesting periods

+ References

No definition available.

+ Details

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- Definition

Fair Value of Restricted Stock Units Which Contain Two and Half Year Vesting Periods

+ References

No definition available.

+ Details

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- Definition

The number of units that cliff vest after three years.

+ References

No definition available.

+ Details

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- Definition

Number of units that vest 50% on each of the third and fourth anniversary of the date of grant.

+ References

No definition available.

+ Details

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- Definition

Number of units that vest on the first anniversary of the date of the grant.

+ References

No definition available.

+ Details

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- Definition

Number of units that vest ratably over a three-year period

+ References

No definition available.

+ Details

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- Definition

Percentage Vested On Each Of Third And Fourth Anniversary Of Grant Date

+ References

No definition available.

+ Details

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of expense, net of income tax, recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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Period Type:	duration

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

+ Details

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Period Type:	instant

- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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Period Type:	duration

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Stock-Based Compensation (Narrative) (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4	$ 3	$ 12	$ 14
Stock-based compensation expense (net of tax)	2	2	7	8
Employee service share based compensation incremental tax benefit to be realized from exercise of stock awards			$ 13
Number of units that cliff vest after three years				262
Number of units that vest 50% on each of the third and fourth anniversary of the date of grant				93
Percentage vested on each of third and fourth anniversary of grant date				50.00%
Number of units that vest ratably over a three-year period (in number of units)				617
Number of units that vest on the first anniversary of the date of the grant (in number of units)				31
Fair value of restricted stock units which contain three-year vesting periods			$ 10.59		$ 11.39
Fair value of restricted stock units which contain two and half year vesting periods			$ 11.93
Fair value of restricted stock units which contain Four-year vesting periods (in dollars per unit)					$ 12.53
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding stock appreciation rights	500		500
Weighted average exercise price	$ 24.40		$ 24.40
Weighted average remaining contractual life (in years)			9 months 18 days
Restricted Stock Units (RSUs) [Member] \| Market-Vesting Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at fair market value (in number of RSUs)			488	355
Share-based compensation vesting period, maximum, years			3 years
Restricted Stock Units (RSUs) [Member] \| Time-based vesting schedule [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at fair market value (in number of RSUs)			835	648
Restricted Stock Units (RSUs) [Member] \| Performance-Based Vesting Schedule [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted at fair market value (in number of RSUs)			486