Represents the maxiumum amount of time a stock option granted by the Company may be outstanding.

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Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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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.

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Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

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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.

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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).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Net number of share options (or share units) granted during the period.

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

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The number of employees affected by the modification of an equity-based compensation plan.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Value, after forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

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Share-Based Payments (Narrative) (Details) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended			49 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended
Share-Based Payments (Narrative) (Details) (USD $)	Feb. 09, 2010 senior_executive	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 09, 2010	Mar. 31, 2014	Feb. 26, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefits related to share-based payment arrangements			$ 3,625,000	$ 3,521,000	$ 2,792,000
Unrecognized compensation expense related to the unvested portion of share-based payments			20,400,000						20,400,000
Compensation expense is expected to be amortized over a weighted-average period			2 years 1 month 6 days
Award vesting period	4 years
Granted (shares)			651,000
Preferred Stock, Shares Outstanding (shares)			0us-gaap_PreferredStockSharesOutstanding	0us-gaap_PreferredStockSharesOutstanding	0us-gaap_PreferredStockSharesOutstanding				0us-gaap_PreferredStockSharesOutstanding
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures		29,100,000
Stock options, expiration term			10 years
Granted (stock options)	500,000		0	0	0	0
Grant value (usd per share)	$ 10.48
Number of senior executives	5
Aggregate intrinsic value of option exercised			1,200,000	3,500,000	600,000
Proceeds from exercise of employee stock options			967,000	4,049,000	966,000
Excess tax benefit from exercise of stock options			300,000	700,000	100,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Sotheby S Incentive Compensation Programs Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		344,692
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures		15,400,000
Mr Ruprecht September2010 Employment Agreement Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		78,511
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures							3,500,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures								28,200,000
Subsequent Event [Member] \| Sotheby S Incentive Compensation Programs Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)								304,882
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures								13,400,000
Subsequent Event [Member] \| Mr Ruprecht September2010 Employment Agreement Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)								79,782
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures								3,500,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Granted (shares)		423,203
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures		18,900,000
Performance Shares [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period								3 years
Granted (shares)								384,664
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures								16,900,000
Equity Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Granted, weighted average exercise price (usd per share)	$ 22.11
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future awards (shares)			3,600,000						3,600,000
Restricted Stock Units (RSUs) [Member] \| Sotheby S Incentive Compensation Programs Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Granted (shares)		227,936
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures		10,200,000
Restricted Stock Units (RSUs) [Member] \| Subsequent Event [Member] \| Sotheby S Incentive Compensation Programs Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period								3 years
Granted (shares)								258,827
Stock Granted During Period, Value, Share-based Compensation, Net of Forfeitures								11,300,000
Restricted Stock Restricted Stock Unit And Performance Share Unit Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of share vested			28,100,000	26,900,000	28,100,000
Equity Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future awards (shares)			104,100						104,100
Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment accelerated recognition									$ 3,600,000