Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 29, 2018
Accounting Policies [Abstract]
Basis of Presentation and Preparation	Basis of Presentation and Preparation The accompanying consolidated financial statements include the accounts of the Company. Intercompany accounts and transactions have been eliminated. In the opinion of the Company’s management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. The preparation of these consolidated financial statements and accompanying notes in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported. Actual results could differ materially from those estimates. Certain prior period amounts in the consolidated financial statements and accompanying notes have been reclassified to conform to the current period’s presentation.
Fiscal Period	The Company’s fiscal year is the 52- or 53-week period that ends on the last Saturday of September. The Company’s fiscal years 2018 and 2016 spanned 52 weeks each, whereas fiscal year 2017 included 53 weeks. A 14th week was included in the first fiscal quarter of 2017, as is done every five or six years, to realign the Company’s fiscal quarters with calendar quarters. Unless otherwise stated, references to particular years, quarters, months and periods refer to the Company’s fiscal years ended in September and the associated quarters, months and periods of those fiscal years.
Revenue Recognition	Revenue Recognition Net sales consist primarily of revenue from the sale of hardware, software, digital content and applications, accessories, and service and support contracts. The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred, the sales price is fixed or determinable and collection is probable. Product is considered delivered to the customer once it has been shipped and title, risk of loss and rewards of ownership have been transferred. For most of the Company’s product sales, these criteria are met at the time the product is shipped. For online sales to individuals, for some sales to education customers in the U.S., and for certain other sales, the Company defers revenue until the customer receives the product because the Company retains a portion of the risk of loss on these sales during transit. For payment terms in excess of the Company’s standard payment terms, revenue is recognized as payments become due unless the Company has positive evidence that the sales price is fixed or determinable, such as a successful history of collection, without concession, on comparable arrangements. The Company recognizes revenue from the sale of hardware products, software bundled with hardware that is essential to the functionality of the hardware and third-party digital content sold on the iTunes Store in accordance with general revenue recognition accounting guidance. The Company recognizes revenue in accordance with industry-specific software accounting guidance for the following types of sales transactions: (i) standalone sales of software products, (ii) sales of software upgrades and (iii) sales of software bundled with hardware not essential to the functionality of the hardware. For the sale of most third-party products, the Company recognizes revenue based on the gross amount billed to customers because the Company establishes its own pricing for such products, retains related inventory risk for physical products, is the primary obligor to the customer and assumes the credit risk for amounts billed to its customers. For third-party applications sold through the App Store and Mac App Store and certain digital content sold through the iTunes Store, the Company does not determine the selling price of the products and is not the primary obligor to the customer. Therefore, the Company accounts for such sales on a net basis by recognizing in net sales only the commission it retains from each sale. The portion of the gross amount billed to customers that is remitted by the Company to third-party app developers and certain digital content owners is not reflected in the Company’s Consolidated Statements of Operations. The Company records deferred revenue when it receives payments in advance of the delivery of products or the performance of services. This includes amounts that have been deferred for unspecified and specified software upgrade rights and non-software services that are attached to hardware and software products. The Company sells gift cards redeemable at its retail and online stores, and also sells gift cards redeemable on iTunes Store, App Store, Mac App Store, TV App Store and Book Store for the purchase of digital content and software. The Company records deferred revenue upon the sale of the card, which is relieved upon redemption of the card by the customer. Revenue from AppleCare service and support contracts is deferred and recognized over the service coverage periods. AppleCare service and support contracts typically include extended phone support, repair services, web-based support resources and diagnostic tools offered under the Company’s standard limited warranty. The Company records reductions to revenue for estimated commitments related to price protection and other customer incentive programs. For transactions involving price protection, the Company recognizes revenue net of the estimated amount to be refunded. For the Company’s other customer incentive programs, the estimated cost of these programs is recognized at the later of the date at which the Company has sold the product or the date at which the program is offered. The Company also records reductions to revenue for expected future product returns based on the Company’s historical experience. Revenue is recorded net of taxes collected from customers that are remitted to governmental authorities, with the collected taxes recorded as current liabilities until remitted to the relevant government authority. Revenue Recognition for Arrangements with Multiple Deliverables For multi-element arrangements that include hardware products containing software essential to the hardware product’s functionality, undelivered software elements that relate to the hardware product’s essential software, and undelivered non-software services, the Company allocates revenue to all deliverables based on their relative selling prices. In such circumstances, the Company uses a hierarchy to determine the selling price to be used for allocating revenue to deliverables: (i) vendor-specific objective evidence of fair value (“VSOE”), (ii) third-party evidence of selling price (“TPE”) and (iii) best estimate of selling price (“ESP”). VSOE generally exists only when the Company sells the deliverable separately and is the price actually charged by the Company for that deliverable. ESPs reflect the Company’s best estimates of what the selling prices of elements would be if they were sold regularly on a stand-alone basis. For multi-element arrangements accounted for in accordance with industry-specific software accounting guidance, the Company allocates revenue to all deliverables based on the VSOE of each element, and if VSOE does not exist revenue is recognized when elements lacking VSOE are delivered. For sales of iPhone, iPad, Mac and certain other products, the Company has indicated it may from time to time provide future unspecified software upgrades to the device’s essential software and/or non-software services free of charge. The Company has identified up to three deliverables regularly included in arrangements involving the sale of these devices. The first deliverable, which represents the substantial portion of the allocated sales price, is the hardware and software essential to the functionality of the hardware device delivered at the time of sale. The second deliverable is the embedded right included with qualifying devices to receive, on a when-and-if-available basis, future unspecified software upgrades relating to the product’s essential software. The third deliverable is the non-software services to be provided to qualifying devices. The Company allocates revenue between these deliverables using the relative selling price method. Because the Company has neither VSOE nor TPE for these deliverables, the allocation of revenue is based on the Company’s ESPs. Revenue allocated to the delivered hardware and the related essential software is recognized at the time of sale, provided the other conditions for revenue recognition have been met. Revenue allocated to the embedded unspecified software upgrade rights and the non-software services is deferred and recognized on a straight-line basis over the estimated period the software upgrades and non-software services are expected to be provided. Cost of sales related to delivered hardware and related essential software, including estimated warranty costs, are recognized at the time of sale. Costs incurred to provide non-software services are recognized as cost of sales as incurred, and engineering and sales and marketing costs are recognized as operating expenses as incurred. The Company’s process for determining its ESP for deliverables without VSOE or TPE considers multiple factors that may vary depending upon the unique facts and circumstances related to each deliverable including, where applicable, prices charged by the Company and market trends in the pricing for similar offerings, product-specific business objectives, estimated cost to provide the non-software services and the relative ESP of the upgrade rights and non-software services as compared to the total selling price of the product.
Shipping Costs	Shipping Costs Amounts billed to customers related to shipping and handling are classified as revenue, and the Company’s shipping and handling costs are classified as cost of sales.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred and included in selling, general and administrative expenses.
Share-Based Compensation	Share-Based Compensation The Company generally measures share-based compensation based on the closing price of the Company’s common stock on the date of grant, and recognizes expense on a straight-line basis for its estimate of equity awards that will ultimately vest. Further information regarding share-based compensation can be found in Note 8, “Benefit Plans.”
New Accounting Pronouncements	During the first quarter of 2018, the Company adopted the Financial Accounting Standards Board’s (the “FASB”) Accounting Standards Update (“ASU”) No. 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”), which modified certain aspects of the accounting for share-based payment transactions, including income taxes, classification of awards and classification in the statement of cash flows. Historically, excess tax benefits or deficiencies from the Company’s equity awards were recorded as additional paid-in capital in its Consolidated Balance Sheets and were classified as a financing activity in its Consolidated Statements of Cash Flows. Beginning in 2018, the Company records any excess tax benefits or deficiencies from its equity awards as part of the provision for income taxes in its Consolidated Statements of Operations in the reporting periods in which equity vesting occurs. The Company elected to apply the cash flow classification requirements related to excess tax benefits retrospectively to all periods presented, which resulted in an increase to cash generated by operating activities in the Consolidated Statements of Cash Flows of $627 million and $407 million for 2017 and 2016, respectively. During the second quarter of 2018, the FASB issued ASU No. 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (“ASU 2018-02”). ASU 2018-02 allows an entity to elect to reclassify the income tax effects of the Act on items within AOCI to retained earnings. The Company elected to apply the provision of ASU 2018-02 in 2018 with a reclassification of net tax benefits related to cumulative foreign currency translation and unrealized gains/losses on derivative instruments and marketable securities, resulting in a $278 million decrease in AOCI and a corresponding increase in retained earnings in the Consolidated Balance Sheet and Consolidated Statement of Shareholders’ Equity.
Cash Equivalents and Marketable Securities	Cash Equivalents and Marketable Securities All highly liquid investments with maturities of three months or less at the date of purchase are classified as cash equivalents. The Company’s marketable debt and equity securities have been classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Marketable equity securities, including mutual funds, are classified as short-term based on the nature of the securities and their availability for use in current operations. The cost of securities sold is determined using the specific identification method.
Inventories	Inventories Inventories are computed using the first-in, first-out method.
Property, Plant and Equipment	Property, Plant and Equipment Depreciation on property, plant and equipment is recognized on a straight-line basis over the estimated useful lives of the assets, which for buildings is the lesser of 30 years or the remaining life of the underlying building; between one and five years for machinery and equipment, including product tooling and manufacturing process equipment; and the shorter of lease term or useful life for leasehold improvements. Capitalized costs related to internal-use software are amortized on a straight-line basis over the estimated useful lives of the assets, which range from three to five years.
Fair Value Measurements	Fair Value Measurements The Company’s valuation techniques used to measure the fair value of money market funds and certain marketable equity securities are derived from quoted prices in active markets for identical assets or liabilities. The valuation techniques used to measure the fair value of the Company’s debt instruments and all other financial instruments, which generally have counterparties with high credit ratings, are based on quoted market prices or model-driven valuations using significant inputs derived from or corroborated by observable market data. Level 2 fair value estimates are based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 1 fair value estimates are based on quoted prices in active markets for identical assets or liabilities.
Derivative Financial Instruments	Derivative Financial Instruments The Company may use derivatives to partially offset its business exposure to foreign currency and interest rate risk on expected future cash flows, net investments in certain foreign subsidiaries, and certain existing assets and liabilities. However, the Company may choose not to hedge certain exposures for a variety of reasons including, but not limited to, accounting considerations or the prohibitive economic cost of hedging particular exposures. There can be no assurance the hedges will offset more than a portion of the financial impact resulting from movements in foreign currency exchange or interest rates. To protect gross margins from fluctuations in foreign currency exchange rates, certain of the Company’s subsidiaries whose functional currency is the U.S. dollar may hedge a portion of forecasted foreign currency revenue, and subsidiaries whose functional currency is not the U.S. dollar may hedge a portion of forecasted inventory purchases not denominated in the subsidiaries’ functional currencies. The Company may enter into forward contracts, option contracts or other instruments to manage this risk and may designate these instruments as cash flow hedges. The Company generally hedges portions of its forecasted foreign currency exposure associated with revenue and inventory purchases, typically for up to 12 months. To protect the net investment in a foreign operation from fluctuations in foreign currency exchange rates, the Company may enter into foreign currency forward and option contracts to offset a portion of the changes in the carrying amounts of these investments due to fluctuations in foreign currency exchange rates. In addition, the Company may use non-derivative financial instruments, such as its foreign currency–denominated debt, as hedges of its net investments in certain foreign subsidiaries. In both of these cases, the Company designates these instruments as net investment hedges. To protect the Company’s foreign currency–denominated term debt or marketable securities from fluctuations in foreign currency exchange rates, the Company may enter into forward contracts, cross-currency swaps or other instruments. These instruments may offset a portion of the foreign currency remeasurement gains or losses, or changes in fair value. The Company may designate these instruments as either cash flow or fair value hedges. As of September 29, 2018, the Company’s hedged term debt– and marketable securities–related foreign currency transactions are expected to be recognized within 24 years. The Company may also enter into non-designated foreign currency contracts to offset a portion of the foreign currency exchange gains and losses generated by the remeasurement of certain assets and liabilities denominated in non-functional currencies. To protect the Company’s foreign currency–denominated term debt or marketable securities from fluctuations in interest rates, the Company may enter into interest rate swaps, options or other instruments. These instruments may offset a portion of the changes in interest income or expense, or changes in fair value. The Company designates these instruments as either cash flow or fair value hedges. As of September 29, 2018, the Company’s hedged interest rate transactions are expected to be recognized within 9 years. Cash Flow Hedges The effective portions of cash flow hedges are recorded in accumulated other comprehensive income/(loss) (“AOCI”) until the hedged item is recognized in earnings. Deferred gains and losses associated with cash flow hedges of foreign currency revenue are recognized as a component of net sales in the same period as the related revenue is recognized, and deferred gains and losses related to cash flow hedges of inventory purchases are recognized as a component of cost of sales in the same period as the related costs are recognized. Deferred gains and losses associated with cash flow hedges of interest income or expense are recognized in other income/(expense), net in the same period as the related income or expense is recognized. For options designated as cash flow hedges, changes in the time value are excluded from the assessment of hedge effectiveness. The ineffective portions and amounts excluded from the effectiveness testing of cash flow hedges are recognized in other income/(expense), net. Derivative instruments designated as cash flow hedges must be de-designated as hedges when it is probable the forecasted hedged transaction will not occur in the initially identified time period or within a subsequent two-month time period. Deferred gains and losses in AOCI associated with such derivative instruments are reclassified into other income/(expense), net in the period of de-designation. Any subsequent changes in fair value of such derivative instruments are reflected in other income/(expense), net unless they are re-designated as hedges of other transactions. Net Investment Hedges The effective portions of net investment hedges are recorded in other comprehensive income/(loss) (“OCI”) as a part of the cumulative translation adjustment. The ineffective portions and amounts excluded from the effectiveness testing of net investment hedges are recognized in other income/(expense), net. For forward exchange contracts designated as net investment hedges, the Company excludes changes in fair value relating to changes in the forward carry component from its definition of effectiveness. Accordingly, any gains or losses related to this forward carry component are recognized in earnings in the current period. Fair Value Hedges Gains and losses related to changes in fair value hedges are recognized in earnings along with a corresponding loss or gain related to the change in value of the underlying hedged item in the same line in the Consolidated Statements of Operations. Non-Designated Derivatives Derivatives that are not designated as hedging instruments are adjusted to fair value through earnings in the financial statement line item to which the derivative relates. The Company records all derivatives in the Consolidated Balance Sheets at fair value. The Company’s accounting treatment for these derivative instruments is based on its hedge designation.
Segment Reporting	Segment Information and Geographic Data The Company reports segment information based on the “management” approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of the Company’s reportable segments. The Company manages its business primarily on a geographic basis. The Company’s reportable segments consist of the Americas, Europe, Greater China, Japan and Rest of Asia Pacific. Americas includes both North and South America. Europe includes European countries, as well as India, the Middle East and Africa. Greater China includes China, Hong Kong and Taiwan. Rest of Asia Pacific includes Australia and those Asian countries not included in the Company’s other reportable segments. Although the reportable segments provide similar hardware and software products and similar services, each one is managed separately to better align with the location of the Company’s customers and distribution partners and the unique market dynamics of each geographic region. The accounting policies of the various segments are the same as those described in Note 1, “Summary of Significant Accounting Policies.” The Company evaluates the performance of its reportable segments based on net sales and operating income. Net sales for geographic segments are generally based on the location of customers and sales through the Company’s retail stores located in those geographic locations. Operating income for each segment includes net sales to third parties, related cost of sales and operating expenses directly attributable to the segment. Advertising expenses are generally included in the geographic segment in which the expenditures are incurred. Operating income for each segment excludes other income and expense and certain expenses managed outside the reportable segments. Costs excluded from segment operating income include various corporate expenses such as research and development, corporate marketing expenses, certain share-based compensation expenses, income taxes, various nonrecurring charges and other separately managed general and administrative costs. The Company does not include intercompany transfers between segments for management reporting purposes.