The maximum period over which the fair value of restricted stock and restricted stock units are amortized.

No definition available.

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- Definition

The historical period upon which annual expected stock price volatility is based.

+ References

No definition available.

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- Definition

The maximum daily treasury yield curve period, in years, upon which average risk-free interest rate is based.

+ References

No definition available.

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- Definition

The minimum daily treasury yield curve period, in years, upon which average risk-free interest rate is based.

+ References

No definition available.

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- Definition

Represents the assumed correlation between the total shareholder return for the entities stock and the S&P 500 Composite Index.

+ References

No definition available.

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- Definition

Represents the maximum expiration period for stock options from the date of grant.

+ References

No definition available.

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- Definition

Represents the amount by which common stock available is reduced for each share of restricted stock and restricted stock unit granted.

+ 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 1

-Subparagraph (b)

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-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

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-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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-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

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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-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.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

+ References

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- Definition

Reductions in the entity's income taxes that arise when compensation cost (from non-qualified share-based compensation) recognized on the entity's tax return exceeds compensation cost from equity-based compensation recognized in financial statements. This element represents the cash inflow reported in the enterprise's financing activities.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph i

-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.

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-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 00-15

-Paragraph 3

-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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 20

-Section 55

-Paragraph 24

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- Definition

Description of the period of time over 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, which may be expressed in a variety of ways (for example, in years, month and year).

+ References

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- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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

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Shareholders' Equity and Stock-Based Compensation (Details 4) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stock-based Compensation
Vesting period (in years)			3 years
Maximum period over which the fair value of restricted stock and restricted stock units are amortized (in years)			three years
Compensation expense			$ 41.4	$ 31.1	$ 27.6
Related tax benefit			15.5	11.6	10.4
Assumptions in determining the fair value of awards granted
Annual expected stock price volatility (as a percent)	61.00%	62.00%
Annual expected dividend yield (as a percent)	1.27%	1.64%
Risk free interest rate (as a percent)	1.03%	1.20%
Correlation between total shareholder return for SPX and S&P 500 Composite Index	0.7559	0.7250
Historical period upon which annual expected stock price volatility is based (in years)			three-year
Minimum daily treasury yield curve period upon which average risk-free interest rate is based (in years)			one-year
Maximum daily treasury yield curve period upon which average risk-free interest rate is based (in years)			three-year
2002 Stock Compensation Plan
Stock-based Compensation
Shares available for grant			5,000,000
Reduction of shares available for grant			2.5
2006 Non-Employee Directors' Stock Incentive Plan ("Directors' Plan")
Stock-based Compensation
Maximum common stock authorized for grant (in shares)			30,000
Stock Options granted to key employees
Stock-based Compensation
Classification of excess tax benefits from stock-based compensation as financing cash flows			$ 6.6	$ 4.2	$ 1.7
Vesting period (in years)			3 years
Maximum expiration period of stock options from date of grant (in years)			10
S&P 500 Composite Index
Stock-based Compensation
Portion of the grant that will vest if the Company outperforms the S&P composite index for the prior year			one-third
Assumptions in determining the fair value of awards granted
Annual expected stock price volatility (as a percent)	30.30%	30.80%
Risk free interest rate (as a percent)	1.03%	1.20%