As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

+ References

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- Definition

The noncash expense that represents the cost of restricted stock or unit distributed to employees as compensation.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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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

Equity-based compensation cost during the period with respect to the award, which will be recognized in income (as well as the total recognized tax benefit) or capitalized as part of the cost of an asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 50

-Section 50

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 64, 65

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Statement of Financial Accounting Standard (FAS)

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-Paragraph A240

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-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

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-Topic 718

-SubTopic 10

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- 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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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

-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 Statement of Financial Accounting Standard (FAS)

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-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

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-Paragraph 2

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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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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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Additionally Authorized

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Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercised, Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercised, Intrinsic Value

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- Definition

Share based compensation by share based payment award, actual award as percentage of target award

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- Definition

Share based compensation by share based payment award options term

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- Definition

Share based compensation by share based payment award, percentage of total award, performance vested cash award

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- Definition

Share based compensation by share based payment award, percentage of total award, performance vested stock award

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- Definition

Share based compensation by share based payment award, percentage of total award, time vested stock options

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Stock-Based Compensation Plans (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended			9 Months Ended							9 Months Ended
	Aug. 31, 2011	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Maximum [Member]	Sep. 30, 2011 Minimum [Member]	Sep. 30, 2011 2007 Plan [Member]	May 31, 2011 2007 Plan [Member]	May 31, 2009 2007 Plan [Member]	Sep. 30, 2011 Executive Officer [Member]	Sep. 30, 2010 Executive Officer [Member]	Sep. 30, 2011 LTIP Awards [Member]
Shares initially approved for issuance									500,000
Shares additionally approved for issuance										2,860,000	325,000
Shares additionally available for future grants		2,480,879			2,480,879
Compensation cost charged to income for stock options		$ 192,000		$ 349,000	$ 567,000	$ 1,300,000
Compensation cost charged to income for restricted share awards		828,000		672,000	2,400,000	2,000,000
Weighted average grant date fair value per share of options granted			$ 32.59		$ 33.16	$ 35.66						$ 14.24	$ 16.39
Aggregate intrinsic value of options exercised					823,000	2,800,000
Restricted stock units, granted			446		90,285	137,656
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition					2.2
Share based payment award options term					7
Award vesting period					three
Actual award as percentage of target award							200.00%	0.00%
Award percentage of total award time vested stock options	25.00%
Percentage of total award, performance vested stock award	25.00%
Percentage of total award, performance vested cash award	50.00%
Unrecognized compensation cost related to non-vested share based arrangements		$ 7,300,000			$ 7,300,000									$ 12,700,000
Nonvested awards, total compensation cost Not yet recognized, period for recognition					2.2