Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Adjustments to Prior Period Presentation—In 2013, General and Administrative Expenses included $1.4 million of third party advisory, legal, and other professional service fees directly associated with issues related to shareholder activism. The costs related to these issues became material in 2014 and, as a result, were reported separately within Special Charges. The comparable costs incurred in 2013 have been reclassified to Special Charges in this Form 10-K. Principles of Consolidation—The Consolidated Financial Statements include the accounts of Sotheby’s wholly-owned subsidiaries and Sotheby's Beijing Auction Co., Ltd. ("Sotheby's Beijing"), a joint venture formed in September 2012 in which Sotheby's has a controlling 80% ownership interest. The net income attributable to the minority owner of Sotheby's Beijing is reported as "Net Income Attributable to Noncontrolling Interest" in the Consolidated Income Statements and the non-controlling 20% ownership interest is recorded as "Noncontrolling Interest" within the Equity section of the Consolidated Balance Sheets. Intercompany transactions and balances among Sotheby's subsidiaries have been eliminated. Equity investments through which Sotheby’s exercises significant influence over the investee, but does not control, are accounted for using the equity method. Under the equity method, Sotheby’s share of investee earnings or losses is recorded, net of tax, within Equity in Earnings of Investees in the Consolidated Income Statements. Sotheby’s interest in the net assets of the investee is recorded within Equity Method Investments on the Consolidated Balance Sheets. (See Note 7 for information related to Sotheby’s equity method investments.) Foreign Currency Translation—Assets and liabilities recorded in foreign currencies are translated at the exchange rate on the balance sheet date. Revenues, expenses, gains, and losses recorded in foreign currencies are translated using the monthly average exchange rates prevailing during the period in which they are recognized. Translation adjustments resulting from this process are recorded to Other Comprehensive Income (Loss) and reported on the Consolidated Balance Sheets within Accumulated Other Comprehensive Income (Loss) until the subsidiary is sold or liquidated. Restricted Cash—Restricted Cash includes net auction proceeds owed to consignors in certain foreign jurisdictions where such funds are legally required to be maintained in segregated bank accounts, as well as other cash deposits whose use is restricted by law, contract or management statement of intention. Valuation of Inventory and Loan Collateral—The market for fine art, decorative art, and jewelry is not a highly liquid trading market. As a result, the valuation of these items is inherently subjective and their realizable value often fluctuates over time. In estimating the realizable value of the property held in inventory and the property pledged as collateral for Finance segment loans, management relies on the opinions of Sotheby’s specialists, who consider the following complex array of factors when valuing these items: (i) whether the property is expected to be offered at auction or sold privately and the timing of any such sale; (ii) the supply and demand for the property, taking into account economic conditions and, where relevant, changing trends in the art market as to which collecting categories and artists are most sought after; and (iii) recent sale prices achieved for comparable items within a particular collecting category and/or by a particular artist. Due to the inherent subjectivity involved in estimating the realizable value of the property held in inventory and the property pledged as collateral for Finance segment loans, management’s estimates of realizable value may prove, with the benefit of hindsight, to be different than the amount ultimately realized upon sale. (See below for a discussion of Sotheby’s accounting policies with respect to Notes Receivable and Inventory.) Accounts Receivable and Allowance for Doubtful Accounts—Accounts Receivable principally includes amounts due from buyers as a result of auction and private sale transactions. The recorded amount reflects the purchase price of the property, including Sotheby's commission. The Allowance for Doubtful Accounts principally includes estimated losses associated with situations when Sotheby's has paid the net sale proceeds to the seller (also known as a consignor) and it is probable that payment will not be collected from the buyer. The Allowance for Doubtful Accounts also includes an estimate of probable losses inherent in the remainder of the Accounts Receivable balance. The amount of the required allowance is based on the facts available to management, including the value of any property held as collateral, and is reevaluated and adjusted as additional facts become known. Based on all available information, management believes that the Allowance for Doubtful Accounts is adequate as of December 31, 2014; however, actual losses may ultimately exceed the recorded allowance. As of December 31, 2014 and 2013, the allowance for doubtful accounts was $7.3 million and $6.8 million, respectively. (See Note 5 for information related to Accounts Receivable.) Notes Receivable and Allowance for Credit Losses—Notes Receivable principally includes secured loans issued by Sotheby’s Finance segment. The determination of whether a specific loan is impaired and the amount of any required allowance is based on the facts available to management and is reevaluated and adjusted as additional facts become known. A loan is considered to be impaired when management determines that it is probable that a portion of the principal and interest owed by the borrower will not be recovered after taking into account the estimated realizable value of the collateral securing the loan, as well as the ability of the borrower to repay any shortfall between the value of the collateral and the amount of the loan. An allowance is also established for probable losses inherent in the remainder of the loan portfolio based on historical data related to loan losses. (See Note 5 for information related to Notes Receivable.) Inventory—Inventory consists of works of fine art, decorative art, and jewelry owned by Sotheby's through its Principal and Agency segments. The inventory of the Principal segment consists of property purchased for the purpose of resale, including the remaining inventory of Noortman Master Paintings (see Note 4). The inventory of the Agency segment consists principally of items obtained as a result of the failure of guaranteed property to sell at auction (see Note 18). To a lesser extent, Agency segment inventory also includes property obtained as a result of buyer defaults in situations when Sotheby's has paid the consignor and property acquired in connection with the settlement of authenticity and other claims. Inventory is valued on a specific identification basis at the lower of cost or management’s estimate of realizable value (i.e., the expected sale price upon disposition). If there is evidence that the estimated realizable value of a specific item held in Inventory is less than its carrying value, a writedown is recorded to reflect management's revised estimate of realizable value. Writedowns to the carrying value of Principal segment inventory are recorded in the Consolidated Income Statements within Cost of Principal Revenues. Writedowns to the carrying value of Agency segment inventory are recorded in the Consolidated Income Statements as a reduction to Agency Revenues (see discussion below under “Auction Guarantee and Inventory Activities”). Although all of the items held in Inventory are available for immediate sale, the timing of eventual sale is difficult to predict due to the high value and unique nature of each item, as well as the cyclical nature of the global art market. Management expects that the items held in Inventory will be sold in the ordinary course of Sotheby's business during the normal operating cycle for such items. (See Note 6 for information related to Inventory.) Fixed Assets—Fixed Assets are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful life of the asset. Buildings are depreciated over a useful life of up to 50 years. Building improvements are depreciated over a useful life of up to 20 years. Furniture and fixtures are depreciated over a useful life of up to 7 years. Leasehold improvements are amortized using the straight-line method over the lesser of the term of the related lease or the estimated useful life of the improvement. Computer software consists of the capitalized cost of purchased computer software, as well as direct external and internal computer software development costs incurred in the acquisition or development of software for internal use. These costs are amortized on a straight-line basis over the estimated useful life of the software, which is typically 10 years for enterprise systems and 3 years for other types of software. (See Note 8 for information related to Fixed Assets.) Goodwill and Other Intangible Assets—Goodwill represents the excess of the purchase price paid over the fair value of net assets acquired in a business combination. Goodwill is not amortized, but it is tested annually for impairment at the reporting unit level as of October 31 and between annual tests if indicators of potential impairment exist. These indicators could include a decline in Sotheby’s stock price and market capitalization, a significant change in the outlook for the reporting unit’s business, lower than expected operating results, increased competition, legal factors, or the sale or disposition of a significant portion of a reporting unit. An impairment loss is recognized for any amount by which the carrying value of a reporting unit’s goodwill exceeds its fair value. The fair value of a reporting unit is estimated by management using a discounted cash flow methodology. Goodwill is attributable to reporting units in the Agency segment and totaled $14 million and $14.5 million as of December 31, 2014 and 2013, respectively, with the changes in the carrying value being attributable solely to foreign currency exchange rate movements. Other intangible assets include an indefinite lived license obtained in conjunction with Sotheby's purchase of a retail wine business in 2008. As of December 31, 2014 and 2013, the accumulated amortization related to other intangible assets was $6.1 million and $6.5 million, respectively. Impairment of Long-Lived Assets—Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. In such situations, long-lived assets are considered impaired when estimated future cash flows (undiscounted and without interest charges) resulting from the use of the asset and its eventual disposition are less than the asset’s carrying amount. In such situations, the asset is written down to the present value of the estimated future cash flows. Factors that are considered when evaluating long-lived assets for impairment include a current expectation that it is more likely than not that the long-lived asset will be sold significantly before the end of its useful life, a significant decrease in the market price of the long-lived asset, and a significant change in the extent or manner in which the long-lived asset is being used. Valuation of Deferred Tax Assets—A valuation allowance is recorded to reduce Sotheby’s deferred tax assets to the amount that is more likely than not to be realized. In assessing the need for the valuation allowance, management considers, among other things, previous losses in certain jurisdictions, projections of future taxable income, and ongoing prudent and feasible tax planning strategies. If management determines that sufficient negative evidence exists (for example, if Sotheby's experiences cumulative three-year losses in a certain jurisdiction), then management will consider recording a valuation allowance against a portion or all of the deferred tax assets in that jurisdiction. If, after recording a valuation allowance, management's projections of future taxable income and other positive evidence considered in evaluating the need for a valuation allowance prove, with the benefit of hindsight, to be inaccurate, it will be more difficult to support the realization of its deferred tax assets. As a result, an additional valuation allowance may be required. Conversely, if, after recording a valuation allowance, management determines that sufficient positive evidence exists in the jurisdiction in which it recorded the valuation allowance (for example, if Sotheby's is no longer in a three-year cumulative loss position in the jurisdiction, and management expects to have future taxable income in that jurisdiction based upon its forecasts and the expected timing of deferred tax asset reversals), management may reverse a portion or all of the valuation allowance in that jurisdiction. (See Note 10 for information related to Income Taxes.) Auction Guarantees—From time to time in the ordinary course of its business, Sotheby’s will guarantee to a consignor a minimum sale price in connection with the sale of property at auction (an “auction guarantee”). In the event that the property sells for less than the guaranteed price, Sotheby’s must perform under the auction guarantee by funding the difference between the sale price at auction and the amount of the auction guarantee. If the property does not sell, the amount of the auction guarantee must be paid, but Sotheby’s has the right to recover such amount through the future sale of the property. The estimated fair value of Sotheby’s obligation to perform under its auction guarantees is recorded on the Consolidated Balance Sheets within Accounts Payable and Accrued Liabilities. This estimated fair value is based on an analysis of historical loss experience related to auction guarantees and does not include the impact of risk-sharing arrangements that may have mitigated all or a portion of any historical losses. (See Note 18 for information related to auction guarantees.) Financial Instruments—Sotheby’s material financial instruments include: (i) Cash and Cash Equivalents, (ii) Restricted Cash, (iii) Notes Receivable, (iv) the York Property Mortgage, (v) the Deferred Compensation Liability and related trust assets, (vi) credit facility borrowings, (vii) Long-Term Debt, and (viii) derivative financial instruments. The carrying amounts of Cash and Cash Equivalents, Restricted Cash, Notes Receivable, and credit facility borrowings do not materially differ from their estimated fair values due to their nature and the variable interest rates associated with each of these financial instruments. (See Notes 9, 17, and 19 for information on the fair value of Sotheby's other financial instruments.) Revenue Recognition (Agency Revenues)—Through its Agency segment, Sotheby’s accepts property on consignment, stimulates buyer interest through professional marketing techniques, and matches sellers (also known as consignors) to buyers through the auction or private sale process. Prior to offering a work of art for sale, Sotheby’s specialists perform significant due diligence activities to authenticate and determine the ownership history of the property being sold. The revenue recognition policy for each of the principal components of Agency Revenues is described below. (1) Auction Commission Revenues—In its role as auctioneer, Sotheby’s accepts property on consignment and matches sellers to buyers through the auction process. Following the auction, Sotheby’s invoices the buyer for the purchase price of the property (including the commission owed by the buyer), collects payment from the buyer, and remits to the consignor the net sale proceeds after deducting its commissions, expenses and applicable taxes and royalties. Sotheby’s auction commissions include those paid by the buyer (“buyer’s premium”) and those paid by the seller (“seller’s commission”) (collectively, “auction commission revenue”), both of which are calculated as a percentage of the hammer price of the property sold at auction. On the fall of the auctioneer’s hammer, the highest bidder becomes legally obligated to pay the full purchase price, which includes the hammer price of the property purchased plus the buyer’s premium, and the seller is legally obligated to relinquish the property in exchange for the hammer price less any seller’s commissions. Auction commission revenue is recognized on the date of the auction sale upon the fall of the auctioneer’s hammer, which is the point in time when Sotheby’s has substantially accomplished what it must do to be entitled to the benefits represented by the auction commission revenue. Subsequent to the date of the auction sale, Sotheby’s remaining obligations for its auction services relate only to the collection of the purchase price from the buyer and the remittance of the net sale proceeds to the seller. These remaining service obligations are not an essential part of the auction services provided by Sotheby’s. Under the standard terms and conditions of its auction sales, Sotheby’s is not obligated to pay the consignor for property that has not been paid for by the buyer, provided that the property has not been released to the buyer. If a buyer defaults on payment, the sale may be cancelled, and the property will be returned to the consignor. Management continually evaluates the collectability of amounts due from individual buyers and only recognizes auction commission revenue when the collection of the amount due from the buyer is reasonably assured. If management determines that it is probable that the buyer will default, a cancelled sale is recorded in the period in which that determination is made and the associated Accounts Receivable balance, including Sotheby's auction commission, is reversed. Management's judgments regarding the collectability of Accounts Receivable are based on an assessment of the buyer's payment history, discussions with the buyer, and the value of any property held as security against the buyer's payment obligation. Management's judgments with respect to the collectability of amounts due from buyers for auction purchases may prove, with the benefit of hindsight, to be incorrect. Historically, cancelled sales have not been material in relation to the aggregate hammer price of property sold at auction. Auction commission revenues are recorded net of commissions owed to third parties, which are principally the result of situations when the buyer’s premium is shared with a consignor or with the counterparty in an auction guarantee risk and reward sharing arrangement (see Note 18). Additionally, in certain situations, auction commissions are shared with third parties who introduce Sotheby’s to consignors who sell property at auction or otherwise facilitate the sale of property at auction. (2) Private Sale Commission Revenues—Private sale commission revenues are earned through the direct brokering of purchases and sales of art. Similar to auction sales, the primary service that Sotheby’s provides in a private sale transaction is the matching of the seller to a buyer in a legally binding transaction. Private sales are initiated either by a client wishing to sell property with Sotheby’s acting as its exclusive agent in the transaction or a prospective buyer who is interested in purchasing a certain work of art privately. Such arrangements are evidenced by a legally binding agreement between Sotheby’s and the seller (a “Seller Agreement”), which outlines the terms of the arrangement, including the desired sale price and the amount or rate of commission to be earned. In certain situations, Sotheby’s may also execute a legally binding agreement with the buyer stipulating the terms of the transaction (a “Buyer Agreement”). The timing of revenue recognition for private sale commissions is evaluated on a case-by-case basis, and in large part, is dependent upon whether a Buyer Agreement has been executed. Additionally, a careful analysis of the individual facts and circumstances is performed for each transaction to fully understand Sotheby’s obligations and performance requirements related to the transaction. In transactions with a Buyer Agreement, Sotheby’s services are performed on the date that the Buyer Agreement is executed. At this point, any remaining service obligations are considered to be inconsequential and perfunctory. Such remaining service obligations normally relate only to the collection of the purchase price from the buyer and the remittance of the net sale proceeds to the seller. These remaining service obligations are not an essential part of the services that Sotheby’s provides in a private sale transaction. In the absence of an executed Buyer Agreement, revenue recognition is deferred until Sotheby’s has performed its substantive service obligations in the transaction and the buyer has paid the full purchase price thereby evidencing the terms of the arrangement. Private sale commission revenues are recorded within Agency Revenues in the Consolidated Income Statements. Private sale commission revenues are recorded net of commissions owed to third parties. In certain situations, commissions are shared with third parties who introduce Sotheby’s to consignors who sell property through a private sale transaction. (3) Auction Guarantee and Inventory Activities—This component of Agency Revenues consists mainly of gains and losses related to auction guarantees including: (i) Sotheby's share of overage or shortfall related to guaranteed property offered or sold at auction, (ii) writedowns to the carrying value of previously guaranteed property that initially failed to sell at auction, and (iii) recoveries and losses on the eventual sale of previously guaranteed property that initially failed to sell at auction. The overage or shortfall related to guaranteed property is generally recognized in the period in which the property is offered at auction. However, a shortfall is recognized prior to the date of the auction if management determines that a loss related to an auction guarantee is probable. In such situations, the amount of the loss is estimated by management based on the difference between the amount of the auction guarantee and the expected selling price of the property, including buyer’s premium. Writedowns to the carrying value of previously guaranteed property that is held in Inventory are recognized in the period in which management determines that the estimated realizable value of the item is less than its carrying value. Recoveries or losses resulting from the eventual sale of previously guaranteed property are recognized in the period in which the sale is completed, title to the property passes to the purchaser, and Sotheby’s has fulfilled its obligations with respect to the transaction, including, but not limited to, delivery of the property. The amount of any such recovery or loss, which is recorded on a net basis, is calculated as the difference between the proceeds received from the eventual sale and the carrying value of the property held in Inventory. Revenue Recognition (Principal Revenues)—Principal revenues predominantly include the proceeds from the sale of Principal segment Inventory and are recognized in the period in which the sale is completed, title to the property passes to the purchaser and Sotheby’s has fulfilled any other obligations that may be relevant to the transaction, including, but not limited to, delivery of the property. The carrying value of Principal segment Inventory sold during a period is recorded within Cost of Principal Revenues. Revenue Recognition (Finance Revenues)—Finance revenues consist principally of interest income earned on Notes Receivable. Such interest income is recognized when earned, based on the amount of the outstanding loan, the applicable interest rate on the loan, and the length of time the loan is outstanding during the period. A non-accrual loan is a loan for which future Finance revenue is not recorded due to management’s determination that it is probable that future interest on the loan is not collectible. Any cash receipts subsequently received on non-accrual loans are first applied to reduce the recorded principal balance of the loan, with any proceeds in excess of the principal balance then applied to interest owed by the borrower. The recognition of Finance revenue may resume on a non-accrual loan if sufficient additional collateral is provided by the borrower or if management becomes aware of other circumstances that indicate that it is probable that the borrower will make future interest payments on the loan. Sales, Use and Value-Added Taxes—Sales, use and value-added taxes assessed by governmental authorities that are both imposed on and concurrent with revenue-producing transactions between Sotheby’s and its clients are reported on a net basis within revenues. Agency Direct Costs—A large portion of Agency Direct Costs relate to sale marketing expenses such as catalogue production and distribution, advertising and promotion costs, and traveling exhibition costs. Such costs are deferred and recorded on the Consolidated Balance Sheets within Prepaid Expenses and Other Current Assets until the date of the sale when they are recognized in the Consolidated Income Statements. Cost of Finance Revenues—The Cost of Finance Revenues includes borrowing costs related to the Finance segment's revolving credit facility, including interest expense, commitment fees, and the amortization of amendment and arrangement fees. The Finance segment's revolving credit facility was initiated in 2014 as a result of the establishment of a separate capital structure whereby client loans are now predominantly funded by borrowings drawn from the credit facility. Share-Based Payments—Sotheby’s grants share-based payment awards as compensation to certain employees. The amount of compensation expense recognized for share-based payments is based on management’s estimate of the number of shares ultimately expected to vest as a result of employee service. For share-based payment awards that vest annually over a multi-year period of service, compensation expense is amortized over the requisite service period according to a graded vesting schedule. For share-based payment awards that vest at the end of a service period, compensation expense is amortized on a straight-line basis over the requisite service period. A substantial portion of the share-based payment awards vest only if Sotheby’s achieves established profitability targets. The amount and timing of compensation expense recognized for such performance-based awards is dependent upon management's quarterly assessment of the likelihood and timing of achieving these future profitability targets. Accordingly, if management's projections of future profitability prove, with the benefit of hindsight, to be inaccurate, the amount of life-to-date and future compensation expense related to share-based payments could significantly increase or decrease. Dividend equivalents related to share-based payments to employees are charged to Retained Earnings. (See Note 14 for information related to share-based payments.) Use of Estimates—The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and could change in the short-term.

Summary of Significant Accounting Policies

Adjustments to Prior Period Presentation—In 2013, General and Administrative Expenses included $1.4 million of third party advisory, legal, and other professional service fees directly associated with issues related to shareholder activism. The costs related to these issues became material in 2014 and, as a result, were reported separately within Special Charges. The comparable costs incurred in 2013 have been reclassified to Special Charges in this Form 10-K.

Principles of Consolidation—The Consolidated Financial Statements include the accounts of Sotheby’s wholly-owned subsidiaries and Sotheby's Beijing Auction Co., Ltd. ("Sotheby's Beijing"), a joint venture formed in September 2012 in which Sotheby's has a controlling 80% ownership interest. The net income attributable to the minority owner of Sotheby's Beijing is reported as "Net Income Attributable to Noncontrolling Interest" in the Consolidated Income Statements and the non-controlling 20% ownership interest is recorded as "Noncontrolling Interest" within the Equity section of the Consolidated Balance Sheets. Intercompany transactions and balances among Sotheby's subsidiaries have been eliminated.

Equity investments through which Sotheby’s exercises significant influence over the investee, but does not control, are accounted for using the equity method. Under the equity method, Sotheby’s share of investee earnings or losses is recorded, net of tax, within Equity in Earnings of Investees in the Consolidated Income Statements. Sotheby’s interest in the net assets of the investee is recorded within Equity Method Investments on the Consolidated Balance Sheets. (See Note 7 for information related to Sotheby’s equity method investments.)

Foreign Currency Translation—Assets and liabilities recorded in foreign currencies are translated at the exchange rate on the balance sheet date. Revenues, expenses, gains, and losses recorded in foreign currencies are translated using the monthly average exchange rates prevailing during the period in which they are recognized. Translation adjustments resulting from this process are recorded to Other Comprehensive Income (Loss) and reported on the Consolidated Balance Sheets within Accumulated Other Comprehensive Income (Loss) until the subsidiary is sold or liquidated.

Restricted Cash—Restricted Cash includes net auction proceeds owed to consignors in certain foreign jurisdictions where such funds are legally required to be maintained in segregated bank accounts, as well as other cash deposits whose use is restricted by law, contract or management statement of intention.

Valuation of Inventory and Loan Collateral—The market for fine art, decorative art, and jewelry is not a highly liquid trading market. As a result, the valuation of these items is inherently subjective and their realizable value often fluctuates over time. In estimating the realizable value of the property held in inventory and the property pledged as collateral for Finance segment loans, management relies on the opinions of Sotheby’s specialists, who consider the following complex array of factors when valuing these items: (i) whether the property is expected to be offered at auction or sold privately and the timing of any such sale; (ii) the supply and demand for the property, taking into account economic conditions and, where relevant, changing trends in the art market as to which collecting categories and artists are most sought after; and (iii) recent sale prices achieved for comparable items within a particular collecting category and/or by a particular artist. Due to the inherent subjectivity involved in estimating the realizable value of the property held in inventory and the property pledged as collateral for Finance segment loans, management’s estimates of realizable value may prove, with the benefit of hindsight, to be different than the amount ultimately realized upon sale. (See below for a discussion of Sotheby’s accounting policies with respect to Notes Receivable and Inventory.)

Accounts Receivable and Allowance for Doubtful Accounts—Accounts Receivable principally includes amounts due from buyers as a result of auction and private sale transactions. The recorded amount reflects the purchase price of the property, including Sotheby's commission. The Allowance for Doubtful Accounts principally includes estimated losses associated with situations when Sotheby's has paid the net sale proceeds to the seller (also known as a consignor) and it is probable that payment will not be collected from the buyer. The Allowance for Doubtful Accounts also includes an estimate of probable losses inherent in the remainder of the Accounts Receivable balance. The amount of the required allowance is based on the facts available to management, including the value of any property held as collateral, and is reevaluated and adjusted as additional facts become known. Based on all available information, management believes that the Allowance for Doubtful Accounts is adequate as of December 31, 2014; however, actual losses may ultimately exceed the recorded allowance. As of December 31, 2014 and 2013, the allowance for doubtful accounts was $7.3 million and $6.8 million, respectively. (See Note 5 for information related to Accounts Receivable.)

Notes Receivable and Allowance for Credit Losses—Notes Receivable principally includes secured loans issued by Sotheby’s Finance segment. The determination of whether a specific loan is impaired and the amount of any required allowance is based on the facts available to management and is reevaluated and adjusted as additional facts become known. A loan is considered to be impaired when management determines that it is probable that a portion of the principal and interest owed by the borrower will not be recovered after taking into account the estimated realizable value of the collateral securing the loan, as well as the ability of the borrower to repay any shortfall between the value of the collateral and the amount of the loan. An allowance is also established for probable losses inherent in the remainder of the loan portfolio based on historical data related to loan losses. (See Note 5 for information related to Notes Receivable.)

Inventory—Inventory consists of works of fine art, decorative art, and jewelry owned by Sotheby's through its Principal and Agency segments. The inventory of the Principal segment consists of property purchased for the purpose of resale, including the remaining inventory of Noortman Master Paintings (see Note 4). The inventory of the Agency segment consists principally of items obtained as a result of the failure of guaranteed property to sell at auction (see Note 18). To a lesser extent, Agency segment inventory also includes property obtained as a result of buyer defaults in situations when Sotheby's has paid the consignor and property acquired in connection with the settlement of authenticity and other claims.

Inventory is valued on a specific identification basis at the lower of cost or management’s estimate of realizable value (i.e., the expected sale price upon disposition). If there is evidence that the estimated realizable value of a specific item held in Inventory is less than its carrying value, a writedown is recorded to reflect management's revised estimate of realizable value. Writedowns to the carrying value of Principal segment inventory are recorded in the Consolidated Income Statements within Cost of Principal Revenues. Writedowns to the carrying value of Agency segment inventory are recorded in the Consolidated Income Statements as a reduction to Agency Revenues (see discussion below under “Auction Guarantee and Inventory Activities”).

Although all of the items held in Inventory are available for immediate sale, the timing of eventual sale is difficult to predict due to the high value and unique nature of each item, as well as the cyclical nature of the global art market. Management expects that the items held in Inventory will be sold in the ordinary course of Sotheby's business during the normal operating cycle for such items.

(See Note 6 for information related to Inventory.)

Fixed Assets—Fixed Assets are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful life of the asset. Buildings are depreciated over a useful life of up to 50 years. Building improvements are depreciated over a useful life of up to 20 years. Furniture and fixtures are depreciated over a useful life of up to 7 years. Leasehold improvements are amortized using the straight-line method over the lesser of the term of the related lease or the estimated useful life of the improvement. Computer software consists of the capitalized cost of purchased computer software, as well as direct external and internal computer software development costs incurred in the acquisition or development of software for internal use. These costs are amortized on a straight-line basis over the estimated useful life of the software, which is typically 10 years for enterprise systems and 3 years for other types of software. (See Note 8 for information related to Fixed Assets.)

Goodwill and Other Intangible Assets—Goodwill represents the excess of the purchase price paid over the fair value of net assets acquired in a business combination. Goodwill is not amortized, but it is tested annually for impairment at the reporting unit level as of October 31 and between annual tests if indicators of potential impairment exist. These indicators could include a decline in Sotheby’s stock price and market capitalization, a significant change in the outlook for the reporting unit’s business, lower than expected operating results, increased competition, legal factors, or the sale or disposition of a significant portion of a reporting unit. An impairment loss is recognized for any amount by which the carrying value of a reporting unit’s goodwill exceeds its fair value. The fair value of a reporting unit is estimated by management using a discounted cash flow methodology. Goodwill is attributable to reporting units in the Agency segment and totaled $14 million and $14.5 million as of December 31, 2014 and 2013, respectively, with the changes in the carrying value being attributable solely to foreign currency exchange rate movements. Other intangible assets include an indefinite lived license obtained in conjunction with Sotheby's purchase of a retail wine business in 2008. As of December 31, 2014 and 2013, the accumulated amortization related to other intangible assets was $6.1 million and $6.5 million, respectively.

Impairment of Long-Lived Assets—Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. In such situations, long-lived assets are considered impaired when estimated future cash flows (undiscounted and without interest charges) resulting from the use of the asset and its eventual disposition are less than the asset’s carrying amount. In such situations, the asset is written down to the present value of the estimated future cash flows. Factors that are considered when evaluating long-lived assets for impairment include a current expectation that it is more likely than not that the long-lived asset will be sold significantly before the end of its useful life, a significant decrease in the market price of the long-lived asset, and a significant change in the extent or manner in which the long-lived asset is being used.

Valuation of Deferred Tax Assets—A valuation allowance is recorded to reduce Sotheby’s deferred tax assets to the amount that is more likely than not to be realized. In assessing the need for the valuation allowance, management considers, among other things, previous losses in certain jurisdictions, projections of future taxable income, and ongoing prudent and feasible tax planning strategies.

If management determines that sufficient negative evidence exists (for example, if Sotheby's experiences cumulative three-year losses in a certain jurisdiction), then management will consider recording a valuation allowance against a portion or all of the deferred tax assets in that jurisdiction. If, after recording a valuation allowance, management's projections of future taxable income and other positive evidence considered in evaluating the need for a valuation allowance prove, with the benefit of hindsight, to be inaccurate, it will be more difficult to support the realization of its deferred tax assets. As a result, an additional valuation allowance may be required.

Conversely, if, after recording a valuation allowance, management determines that sufficient positive evidence exists in the jurisdiction in which it recorded the valuation allowance (for example, if Sotheby's is no longer in a three-year cumulative loss position in the jurisdiction, and management expects to have future taxable income in that jurisdiction based upon its forecasts and the expected timing of deferred tax asset reversals), management may reverse a portion or all of the valuation allowance in that jurisdiction.

(See Note 10 for information related to Income Taxes.)

Auction Guarantees—From time to time in the ordinary course of its business, Sotheby’s will guarantee to a consignor a minimum sale price in connection with the sale of property at auction (an “auction guarantee”). In the event that the property sells for less than the guaranteed price, Sotheby’s must perform under the auction guarantee by funding the difference between the sale price at auction and the amount of the auction guarantee. If the property does not sell, the amount of the auction guarantee must be paid, but Sotheby’s has the right to recover such amount through the future sale of the property. The estimated fair value of Sotheby’s obligation to perform under its auction guarantees is recorded on the Consolidated Balance Sheets within Accounts Payable and Accrued Liabilities. This estimated fair value is based on an analysis of historical loss experience related to auction guarantees and does not include the impact of risk-sharing arrangements that may have mitigated all or a portion of any historical losses. (See Note 18 for information related to auction guarantees.)

Financial Instruments—Sotheby’s material financial instruments include: (i) Cash and Cash Equivalents, (ii) Restricted Cash, (iii) Notes Receivable, (iv) the York Property Mortgage, (v) the Deferred Compensation Liability and related trust assets, (vi) credit facility borrowings, (vii) Long-Term Debt, and (viii) derivative financial instruments. The carrying amounts of Cash and Cash Equivalents, Restricted Cash, Notes Receivable, and credit facility borrowings do not materially differ from their estimated fair values due to their nature and the variable interest rates associated with each of these financial instruments. (See Notes 9, 17, and 19 for information on the fair value of Sotheby's other financial instruments.)

Revenue Recognition (Agency Revenues)—Through its Agency segment, Sotheby’s accepts property on consignment, stimulates buyer interest through professional marketing techniques, and matches sellers (also known as consignors) to buyers through the auction or private sale process. Prior to offering a work of art for sale, Sotheby’s specialists perform significant due diligence activities to authenticate and determine the ownership history of the property being sold. The revenue recognition policy for each of the principal components of Agency Revenues is described below.

(1) Auction Commission Revenues—In its role as auctioneer, Sotheby’s accepts property on consignment and matches sellers to buyers through the auction process. Following the auction, Sotheby’s invoices the buyer for the purchase price of the property (including the commission owed by the buyer), collects payment from the buyer, and remits to the consignor the net sale proceeds after deducting its commissions, expenses and applicable taxes and royalties. Sotheby’s auction commissions include those paid by the buyer (“buyer’s premium”) and those paid by the seller (“seller’s commission”) (collectively, “auction commission revenue”), both of which are calculated as a percentage of the hammer price of the property sold at auction.

On the fall of the auctioneer’s hammer, the highest bidder becomes legally obligated to pay the full purchase price, which includes the hammer price of the property purchased plus the buyer’s premium, and the seller is legally obligated to relinquish the property in exchange for the hammer price less any seller’s commissions. Auction commission revenue is recognized on the date of the auction sale upon the fall of the auctioneer’s hammer, which is the point in time when Sotheby’s has substantially accomplished what it must do to be entitled to the benefits represented by the auction commission revenue. Subsequent to the date of the auction sale, Sotheby’s remaining obligations for its auction services relate only to the collection of the purchase price from the buyer and the remittance of the net sale proceeds to the seller. These remaining service obligations are not an essential part of the auction services provided by Sotheby’s.

Under the standard terms and conditions of its auction sales, Sotheby’s is not obligated to pay the consignor for property that has not been paid for by the buyer, provided that the property has not been released to the buyer. If a buyer defaults on payment, the sale may be cancelled, and the property will be returned to the consignor. Management continually evaluates the collectability of amounts due from individual buyers and only recognizes auction commission revenue when the collection of the amount due from the buyer is reasonably assured. If management determines that it is probable that the buyer will default, a cancelled sale is recorded in the period in which that determination is made and the associated Accounts Receivable balance, including Sotheby's auction commission, is reversed. Management's judgments regarding the collectability of Accounts Receivable are based on an assessment of the buyer's payment history, discussions with the buyer, and the value of any property held as security against the buyer's payment obligation. Management's judgments with respect to the collectability of amounts due from buyers for auction purchases may prove, with the benefit of hindsight, to be incorrect. Historically, cancelled sales have not been material in relation to the aggregate hammer price of property sold at auction.

Auction commission revenues are recorded net of commissions owed to third parties, which are principally the result of situations when the buyer’s premium is shared with a consignor or with the counterparty in an auction guarantee risk and reward sharing arrangement (see Note 18). Additionally, in certain situations, auction commissions are shared with third parties who introduce Sotheby’s to consignors who sell property at auction or otherwise facilitate the sale of property at auction.

(2) Private Sale Commission Revenues—Private sale commission revenues are earned through the direct brokering of purchases and sales of art. Similar to auction sales, the primary service that Sotheby’s provides in a private sale transaction is the matching of the seller to a buyer in a legally binding transaction. Private sales are initiated either by a client wishing to sell property with Sotheby’s acting as its exclusive agent in the transaction or a prospective buyer who is interested in purchasing a certain work of art privately. Such arrangements are evidenced by a legally binding agreement between Sotheby’s and the seller (a “Seller Agreement”), which outlines the terms of the arrangement, including the desired sale price and the amount or rate of commission to be earned. In certain situations, Sotheby’s may also execute a legally binding agreement with the buyer stipulating the terms of the transaction (a “Buyer Agreement”).

The timing of revenue recognition for private sale commissions is evaluated on a case-by-case basis, and in large part, is dependent upon whether a Buyer Agreement has been executed. Additionally, a careful analysis of the individual facts and circumstances is performed for each transaction to fully understand Sotheby’s obligations and performance requirements related to the transaction.

In transactions with a Buyer Agreement, Sotheby’s services are performed on the date that the Buyer Agreement is executed. At this point, any remaining service obligations are considered to be inconsequential and perfunctory. Such remaining service obligations normally relate only to the collection of the purchase price from the buyer and the remittance of the net sale proceeds to the seller. These remaining service obligations are not an essential part of the services that Sotheby’s provides in a private sale transaction. In the absence of an executed Buyer Agreement, revenue recognition is deferred until Sotheby’s has performed its substantive service obligations in the transaction and the buyer has paid the full purchase price thereby evidencing the terms of the arrangement.

Private sale commission revenues are recorded within Agency Revenues in the Consolidated Income Statements. Private sale commission revenues are recorded net of commissions owed to third parties. In certain situations, commissions are shared with third parties who introduce Sotheby’s to consignors who sell property through a private sale transaction.

(3) Auction Guarantee and Inventory Activities—This component of Agency Revenues consists mainly of gains and losses related to auction guarantees including: (i) Sotheby's share of overage or shortfall related to guaranteed property offered or sold at auction, (ii) writedowns to the carrying value of previously guaranteed property that initially failed to sell at auction, and (iii) recoveries and losses on the eventual sale of previously guaranteed property that initially failed to sell at auction.

The overage or shortfall related to guaranteed property is generally recognized in the period in which the property is offered at auction. However, a shortfall is recognized prior to the date of the auction if management determines that a loss related to an auction guarantee is probable. In such situations, the amount of the loss is estimated by management based on the difference between the amount of the auction guarantee and the expected selling price of the property, including buyer’s premium.

Writedowns to the carrying value of previously guaranteed property that is held in Inventory are recognized in the period in which management determines that the estimated realizable value of the item is less than its carrying value. Recoveries or losses resulting from the eventual sale of previously guaranteed property are recognized in the period in which the sale is completed, title to the property passes to the purchaser, and Sotheby’s has fulfilled its obligations with respect to the transaction, including, but not limited to, delivery of the property. The amount of any such recovery or loss, which is recorded on a net basis, is calculated as the difference between the proceeds received from the eventual sale and the carrying value of the property held in Inventory.

Revenue Recognition (Principal Revenues)—Principal revenues predominantly include the proceeds from the sale of Principal segment Inventory and are recognized in the period in which the sale is completed, title to the property passes to the purchaser and Sotheby’s has fulfilled any other obligations that may be relevant to the transaction, including, but not limited to, delivery of the property. The carrying value of Principal segment Inventory sold during a period is recorded within Cost of Principal Revenues.

Revenue Recognition (Finance Revenues)—Finance revenues consist principally of interest income earned on Notes Receivable. Such interest income is recognized when earned, based on the amount of the outstanding loan, the applicable interest rate on the loan, and the length of time the loan is outstanding during the period. A non-accrual loan is a loan for which future Finance revenue is not recorded due to management’s determination that it is probable that future interest on the loan is not collectible. Any cash receipts subsequently received on non-accrual loans are first applied to reduce the recorded principal balance of the loan, with any proceeds in excess of the principal balance then applied to interest owed by the borrower. The recognition of Finance revenue may resume on a non-accrual loan if sufficient additional collateral is provided by the borrower or if management becomes aware of other circumstances that indicate that it is probable that the borrower will make future interest payments on the loan.

Sales, Use and Value-Added Taxes—Sales, use and value-added taxes assessed by governmental authorities that are both imposed on and concurrent with revenue-producing transactions between Sotheby’s and its clients are reported on a net basis within revenues.

Agency Direct Costs—A large portion of Agency Direct Costs relate to sale marketing expenses such as catalogue production and distribution, advertising and promotion costs, and traveling exhibition costs. Such costs are deferred and recorded on the Consolidated Balance Sheets within Prepaid Expenses and Other Current Assets until the date of the sale when they are recognized in the Consolidated Income Statements.

Cost of Finance Revenues—The Cost of Finance Revenues includes borrowing costs related to the Finance segment's revolving credit facility, including interest expense, commitment fees, and the amortization of amendment and arrangement fees. The Finance segment's revolving credit facility was initiated in 2014 as a result of the establishment of a separate capital structure whereby client loans are now predominantly funded by borrowings drawn from the credit facility.

Share-Based Payments—Sotheby’s grants share-based payment awards as compensation to certain employees. The amount of compensation expense recognized for share-based payments is based on management’s estimate of the number of shares ultimately expected to vest as a result of employee service. For share-based payment awards that vest annually over a multi-year period of service, compensation expense is amortized over the requisite service period according to a graded vesting schedule. For share-based payment awards that vest at the end of a service period, compensation expense is amortized on a straight-line basis over the requisite service period.

A substantial portion of the share-based payment awards vest only if Sotheby’s achieves established profitability targets. The amount and timing of compensation expense recognized for such performance-based awards is dependent upon management's quarterly assessment of the likelihood and timing of achieving these future profitability targets. Accordingly, if management's projections of future profitability prove, with the benefit of hindsight, to be inaccurate, the amount of life-to-date and future compensation expense related to share-based payments could significantly increase or decrease.

Dividend equivalents related to share-based payments to employees are charged to Retained Earnings.

(See Note 14 for information related to share-based payments.)

Use of Estimates—The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and could change in the short-term.