Common Stock - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended
Jan. 31, 2013	Mar. 31, 2013	Mar. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation, effect on earnings per share, basic		$ 0.04	$ 0.03
Share-based compensation, effect on earnings per share, diluted		$ 0.03	$ 0.03
Share based compensation		$ 5	$ 4
Weighted average grant-date fair value of options granted		$ 19.84	$ 17.35
Total fair value of shares vested		3	3
Stock Repurchased during Period, Shares	550,000	0
Stock repurchase duration in 2012		12 months
Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		9
Unrecognized compensation costs, weighted average period		1 year 10 months 24 days
Cash received from stock option exercises		2	1
Unrecorded tax benefit from stock options exercised		1	1
Restricted Stock, Restricted Stock Units, Long Term Performance Units, SARs [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		19
Unrecognized compensation costs, weighted average period		2 years 4 months 24 days
Share based compensation		5	6
Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		10
Unrecognized compensation costs, weighted average period		2 years 1 month 6 days
Total fair value of restricted shares vested		5	4
Selling, General and Administrative Expenses [Member] \| Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense related to nonqualified stock options		$ 2	$ 2

Future stock repurchase duration.

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- Definition

Share-based compensation arrangement by share-based payment award options vested.

+ References

No definition available.

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- Definition

Share-based Compensation, Effect on Earnings Per Share, Basic

+ References

No definition available.

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- Definition

Share-based Compensation, Effect on Earnings Per Share, Diluted

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No definition available.

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- Definition

Share-based compensation nonvested awards total compensation cost not yet recognized.

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- Definition

Share-based compensation nonvested awards total compensation cost not yet recognized period for recognition.

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- Definition

Excess tax benefits generated by exercising stock options which are unrecorded due to federal and state net operating losses which are not currently being utilized.

+ References

No definition available.

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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)

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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-Number 123R

-Paragraph 64

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

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- Definition

The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph i

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (a)

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-Name Accounting Standards Codification

-Glossary Financing Activities

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-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 19

-Subparagraph a

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-Number 95

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-Paragraph 2

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

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- Definition

The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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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.

+ References

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Section B

-Paragraph 11A

-Chapter 1

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

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-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

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-Name Regulation S-X (SX)

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-Name Accounting Standards Codification

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