Accounting Policies (Policies)	3 Months Ended
Accounting Policies (Policies)	Mar. 31, 2019
Accounting Policies [Abstract]
Unaudited Interim Financial Information	Unaudited Interim Financial Information We have prepared the accompanying consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. These consolidated financial statements are unaudited and, in our opinion, include all adjustments, consisting of normal recurring adjustments and accruals necessary for a fair presentation of our consolidated balance sheets, operating results, and cash flows for the periods presented. Operating results for the periods presented are not necessarily indicative of the results that may be expected for 2019 due to seasonal and other factors. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) have been omitted in accordance with the rules and regulations of the SEC. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes in Item 8 of Part II, “Financial Statements and Supplementary Data,” of our 2018 Annual Report on Form 10-K.
Prior Period Reclassifications	Prior Period Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation, including the reclassification of long-term capital lease obligations that existed at December 31, 2018 from “Other long-term liabilities” to “Long-term lease liabilities” within the consolidated balance sheets, as a result of the adoption of new accounting guidance for leases. See “Accounting Pronouncements Recently Adopted.”
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Amazon.com, Inc., its wholly-owned subsidiaries, and those entities in which we have a variable interest and of which we are the primary beneficiary, including certain entities in India and China and that support our seller lending financing activities (collectively, the “Company”). Intercompany balances and transactions between consolidated entities are eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and related disclosures of contingent liabilities in the consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, income taxes, commitments and contingencies, valuation of acquired intangibles and goodwill, stock-based compensation forfeiture rates, vendor funding, and inventory valuation. Actual results could differ materially from those estimates.
Earnings per Share	Earnings per Share Basic earnings per share is calculated using our weighted-average outstanding common shares. Diluted earnings per share is calculated using our weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. In periods when we have a net loss, stock awards are excluded from our calculation of earnings per share as their inclusion would have an antidilutive effect.
Accounts Receivable, Net and Other	Accounts Receivable, Net and Other Included in “Accounts receivable, net and other” on our consolidated balance sheets are amounts primarily related to customers, vendors, and sellers. As of December 31, 2018 and March 31, 2019, customer receivables, net, were $9.4 billion and $9.8 billion, vendor receivables, net, were $3.2 billion and $2.5 billion, and seller receivables, net, were $710 million and $660 million. Seller receivables are amounts due from sellers related to our seller lending program, which provides funding to sellers primarily to procure inventory.
Leases	Leases We categorize leases with contractual terms longer than twelve months as either operating or finance. Finance leases are generally those leases that allow us to substantially utilize or pay for the entire asset over its estimated life. Assets acquired under finance leases are recorded in property and equipment, net. All other leases are categorized as operating leases. Our leases generally have terms that range from two to ten years for equipment and two to twenty years for property. Certain lease contracts include obligations to pay for other services, such as operations and maintenance. For leases of property, we account for these other services as a component of the lease. For substantially all other leases, the services are accounted for separately and we allocate payments to the lease and other services components based on estimated stand-alone prices. Lease liabilities are recognized at the present value of the fixed lease payments, reduced by landlord incentives using a discount rate based on similarly secured borrowings available to us. Lease assets are recognized based on the initial present value of the fixed lease payments, reduced by landlord incentives, plus any direct costs from executing the leases. Lease assets are tested for impairment in the same manner as long-lived assets used in operations. Leasehold improvements are capitalized at cost and amortized over the lesser of their expected useful life or the lease term. When we have the option to extend the lease term, terminate the lease before the contractual expiration date, or purchase the leased asset, and it is reasonably certain that we will exercise the option, we consider these options in determining the classification and measurement of the lease. Our leases may include variable payments based on measures that include changes in price indices, market interest rates, or the level of sales at a physical store, which are expensed as incurred. Costs associated with operating lease assets are recognized on a straight-line basis within operating expenses over the term of the lease. Finance lease assets are amortized within operating expenses on a straight-line basis over the shorter of the estimated useful lives of the assets or the lease term. The interest component of a finance lease is included in interest expense and recognized using the effective interest method over the lease term.
Financing Obligations	Financing Obligations We record assets and liabilities for estimated construction costs under build-to-suit lease arrangements when we have control over the building during the construction period. If we continue to control the building after the construction period, the arrangement is classified as a financing obligation instead of a lease. The building is depreciated over the shorter of its useful life or the term of the obligation. If we do not control the building after the construction period ends, the assets and liabilities for construction costs are derecognized, and we classify the lease as either operating or finance.
Video And Music Content	Digital Video and Music Content We obtain video content, inclusive of episodic television and movies, and music content for customers through licensing agreements that have a wide range of licensing provisions including both fixed and variable payment schedules. When the license fee for a specific video or music title is determinable or reasonably estimable and the content is available to us, we recognize an asset and a corresponding liability for the amounts owed. We reduce the liability as payments are made and we amortize the asset to “Cost of sales” on an accelerated basis, based on estimated usage or viewing patterns, or on a straight-line basis. If the licensing fee is not determinable or reasonably estimable, no asset or liability is recorded and licensing costs are expensed as incurred. We also develop original video content for which the production costs are capitalized and amortized to “Cost of sales” predominantly on an accelerated basis that follows the viewing patterns associated with the content. The weighted average remaining life of our capitalized video content is 2.6 years. Our produced and licensed video content is primarily monetized together as a unit, referred to as a film group, in each major geography where we offer Amazon Prime memberships. These film groups are evaluated for impairment whenever an event occurs or circumstances change indicating the fair value is less than the carrying value. The total capitalized costs of video, which is primarily released content, and music as of December 31, 2018 and March 31, 2019 were $3.8 billion and $4.2 billion. Total video and music expense was $1.5 billion and $1.7 billion in Q1 2018 and Q1 2019. Total video and music expense includes licensing and production costs associated with content offered within Amazon Prime memberships, and costs associated with digital subscriptions and sold or rented content.
Unearned Revenue	Unearned Revenue Unearned revenue is recorded when payments are received or due in advance of performing our service obligations and is recognized over the service period. Unearned revenue primarily relates to prepayments of AWS services and Amazon Prime memberships. Our total unearned revenue as of December 31, 2018 was $7.9 billion, of which $2.8 billion was recognized as revenue during the three months ended March 31, 2019. Included in “Other long-term liabilities” on our consolidated balance sheets was $1.4 billion of unearned revenue as of December 31, 2018 and March 31, 2019. Additionally, we have performance obligations, primarily related to AWS, associated with commitments in customer contracts for future services that have not yet been recognized in our financial statements. For contracts with original terms that exceed one year, those commitments not yet recognized were $21.6 billion as of March 31, 2019. The weighted average remaining life of our long-term contracts is 3.3 years. However, the amount and timing of revenue recognition is largely driven by customer usage, which can extend beyond the original contractual term.
Accounting Pronouncements Recently Adopted	Accounting Pronouncements Recently Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued an Accounting Standards Update (“ASU”) amending the accounting for leases, primarily requiring the recognition of lease assets and liabilities for operating leases with terms of more than twelve months on our consolidated balance sheets. Under the new guidance, leases previously described as capital lease obligations and finance lease obligations are now referred to as finance leases and financing obligations, respectively. We adopted this ASU on January 1, 2019 by recording an immaterial cumulative adjustment to retained earnings rather than retrospectively adjusting prior periods. Prior period amounts were not adjusted and continue to be reported in accordance with our historic accounting policies resulting in a balance sheet presentation that is not comparable to the prior period in the first year of adoption. The adoption of this ASU resulted in the recognition of operating lease assets and liabilities of approximately $21 billion, which included the reclassification of finance lease obligations to operating leases of $1.2 billion. As of December 31, 2018, amounts related to finance lease obligations and construction liabilities totaled $9.6 billion, of which $1.5 billion was derecognized for buildings that we do not control during the construction period and $5.4 billion and $1.5 billion were reclassified to finance leases and operating leases, respectively. In March 2019, the FASB issued an ASU amending the accounting for film costs, inclusive of episodic television and movie costs. The new guidance aligns the accounting for production costs of episodic television with that of movies by requiring production costs to be capitalized. Previously, we only capitalized a portion of the production costs related to our produced episodic television content. We adopted this ASU as of January 1, 2019 and began capitalizing substantially all of our production costs. Adoption of this ASU resulted in approximately $130 million of incremental capitalized film costs classified in “Other Assets” for the period ended March 31, 2019.