The grant date fair value of performance share units granted in the current period.

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Represents the benefit recognized during the period arising from share-based compensation arrangements with employees, directors, and certain consultants qualifying for treatment as employees.

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Amount of shares of Company common stock initially issued to purchase a business.

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Amount of shares of Company common stock that will be transferred back the Company as a result of the failure of an acquired business to achieve a minimum level of financial performance.

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The maximum percentage of initial consideration that could be transferred back to the Company.

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The range of the fair value of the performance share units to be awarded annually to the Company's chief executive officer in periods defined by the officer's employment agreement.

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Stock Option Expiration Period

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Stock Option Vesting Period

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Tax benefit associated with any share-based compensation plan other than an employee stock ownership plan (ESOP). The tax benefit results from the deduction by the entity on its tax return for an award of stock that exceeds the cumulative compensation cost for common stock or preferred stock recognized for financial reporting. Includes any resulting tax benefit that exceeds the previously recognized deferred tax asset (excess tax benefits).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 62

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Subparagraph g(1)

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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Aggregate cash, stock, and paid-in-kind dividends declared for all securities (common shares, preferred shares) during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 01-6
-Paragraph 14
-Subparagraph l

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The per share amount of a dividend declared, but not paid, as of the financial reporting date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 32

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph h

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Subparagraph h

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- Definition

The cash outflow from the entity's earnings to the shareholders.

+ References

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- Definition

The cash inflow associated with the amount received from holders exercising their stock options.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 19
-Subparagraph a

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The number of shares issuable under a share-based award plan pertaining to grants made during the period on other than stock option plans (for example, phantom stock plan, stock appreciation rights plan, performance target plan).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph A240
-Subparagraph b(2)(c)

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The decrease in the number of shares potentially issuable under a share-based award plan pertaining to awards for which the grantee has gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

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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)(d)

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph c(2)

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

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the 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 c(2)

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- Definition

Reductions in the entity's income taxes that arise when compensation cost (from non-qualified stock options) recognized on the entity's tax return exceeds compensation cost from non-qualified stock options recognized on the income statement. This element increases net cash provided by operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A132

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Share-Based Payments And Dividends (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended				6 Months Ended		3 Months Ended	1 Months Ended	3 Months Ended		3 Months Ended	6 Months Ended		1 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Aug. 03, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Mar. 31, 2011 Sotheby's Incentive Compensation Programs [Member]	Mar. 31, 2011 Mr. Ruprecht September 2010 Employment Agreement [Member]	Mar. 31, 2011 Mr. Ruprecht September 2010 Employment Agreement [Member]	Jun. 30, 2011 Restricted Stock Units [Member]	Mar. 31, 2011 Performance Share Units [Member]	Jun. 30, 2011 Restricted Stock, RSU's And PSU's [Member]	Jun. 30, 2010 Restricted Stock, RSU's And PSU's [Member]	Dec. 31, 2009 Stock Option [Member]	Jun. 30, 2010 Stock Option [Member]	Jun. 30, 2011 Common Stock Transfer [Member]	Jun. 30, 2011 Common Stock Transfer [Member]	Dec. 31, 2010 Minimum [Member]	Jun. 30, 2011 Maximum [Member]	Dec. 31, 2010 Maximum [Member]
Excess tax benefits related to share-based payment arrangements						$ 7,200,000
Unrecognized compensation expense related to the unvested portion of share-based payments			29,600,000			29,600,000
Compensation expense is expected to be amortized over a weighted-average period (years)						3.3
Stock granted during period																			3,500,000		4,500,000
Granted, Shares								526,903		100,663		627,566	628,000
Vested, Shares				242,539					120,000				988,000
Grant date fair value				26,200,000				22,000,000		4,250,000
Fair value of share vested													44,900,000	17,800,000
Shares available for future awards											1,600,000
Stock option vesting period after date of grant (years)						4
Stock option expiration period after date of grant (years)						10
Aggregate intrinsic value of option exercised						3,200,000	2,000,000
Proceeds from exercise of employee stock options						2,566,000	9,347,000								4,100,000	5,300,000
Excess tax benefits realized from the exercise of stock options						800,000	600,000
Initial consideration (shares)						1,946,849
Percentage of initial consideration transferred back																				20.00%
Common stock transferred		150,000
Share based compensation expense			5,669,000		4,786,000	10,399,000	10,636,000										200,000
Share based compensation benefit																	600,000	600,000
Dividend paid			3,400,000			6,900,000
Dividend declared per share	$ 0.05
Dividends declared	$ 3,400,000