Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 29, 2018
Accounting Policies [Abstract]
Basis of Presentation and Preparation	Basis of Presentation and Preparation The accompanying condensed 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 condensed consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. The preparation of these condensed consolidated financial statements and accompanying notes in conformity with U.S. generally accepted accounting principles 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 condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period’s presentation. These condensed consolidated financial statements and accompanying notes should be read in conjunction with the Company’s annual consolidated financial statements and the notes thereto included in its Annual Report on Form 10-K for the fiscal year ended September 29, 2018 (the “2018 Form 10-K”).
Fiscal Period	The Company’s fiscal year is the 52- or 53-week period that ends on the last Saturday of September. A 14th week is included in the first fiscal quarter every five or six years to realign the Company’s fiscal quarters with calendar quarters. The Company’s fiscal years 2019 and 2018 span 52 weeks each. 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.
New Accounting Pronouncements	Revenue Recognition In the first quarter of 2019, the Company adopted the Financial Accounting Standards Board’s (the “FASB”) Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”), and additional ASUs issued to clarify the guidance in ASU 2014-09 (collectively the “new revenue standard”), which amends the existing accounting standards for revenue recognition. The Company adopted the new revenue standard utilizing the full retrospective transition method. The Company did not restate total net sales in the prior periods presented, as adoption of the new revenue standard did not have a material impact on previously reported amounts. Additionally, beginning in the first quarter of 2019, the Company classified the amortization of the deferred value of Maps, Siri^® and free iCloud services, which are bundled in the sales price of iPhone, Mac, iPad and certain other products, in Services net sales. Historically, the Company classified the amortization of these amounts in Products net sales consistent with its management reporting framework. As a result, Products and Services net sales information for the first quarter of 2018 was reclassified to conform to the 2019 presentation. Financial Instruments In the first quarter of 2019, the Company adopted FASB ASU No. 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which updates certain aspects of the recognition, measurement, presentation and disclosure of financial instruments. The adoption of ASU 2016-01 did not have a material impact on the Company’s condensed consolidated financial statements. Income Taxes In the first quarter of 2019, the Company adopted FASB ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory (“ASU 2016-16”), which requires the recognition of the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. The Company adopted ASU 2016-16 utilizing the modified retrospective transition method. Upon adoption, the Company recorded $2.7 billion of net deferred tax assets, reduced other non-current assets by $128 million, and increased retained earnings by $2.6 billion on its Condensed Consolidated Balance Sheet. The Company will recognize incremental deferred income tax expense as these net deferred tax assets are utilized.
Revenue Recognition	Net sales consist of revenue from the sale of iPhone, Mac, iPad, services and other products. The Company recognizes revenue at the amount to which it expects to be entitled when control of the products or services is transferred to its customers. Control is generally transferred when the Company has a present right to payment and title and the significant risks and rewards of ownership of products or services are transferred to its customers. For most of the Company’s products net sales, control transfers when products are shipped. For the Company’s services net sales, control transfers over time as services are delivered. Payment for products and services net sales is collected within a short period of time following transfer of control or commencement of delivery of services, as applicable. The Company records reductions to products net sales related to future product returns, price protection and other customer incentive programs based on the Company’s expectations and historical experience. For arrangements with multiple performance obligations, which represent promises within an arrangement that are capable of being distinct, the Company allocates revenue to all distinct performance obligations based on their relative stand-alone selling prices (“SSP”). When available, the Company uses observable prices to determine the SSP. When observable prices are not available, SSPs are established that reflect the Company’s best estimates of what the selling prices of the performance obligations would be if they were sold regularly on a stand-alone basis. The Company’s process for estimating SSPs without observable prices considers multiple factors that may vary depending upon the unique facts and circumstances related to each performance obligation including, where applicable, prices charged by the Company for similar offerings, market trends in the pricing for similar offerings, product-specific business objectives and the estimated cost to provide the performance obligation. The Company has identified up to three performance obligations regularly included in arrangements involving the sale of iPhone, Mac, iPad and certain other products. The first performance obligation, which represents the substantial portion of the allocated sales price, is the hardware and bundled software delivered at the time of sale. The second performance obligation is the right to receive certain product-related bundled services, which include iCloud, Siri and Maps. The third performance obligation is the right to receive, on a when-and-if-available basis, future unspecified software upgrades relating to the software bundled with each device. The Company allocates revenue and any related discounts to these performance obligations based on their relative SSPs. Because the Company lacks observable prices for the undelivered performance obligations, the allocation of revenue is based on the Company’s estimated SSPs. Revenue allocated to the delivered hardware and bundled software is recognized when control has transferred to the customer, which generally occurs when the product is shipped. Revenue allocated to the product-related bundled services and unspecified software upgrade rights is deferred and recognized on a straight-line basis over the estimated period they are expected to be provided. Cost of sales related to delivered hardware and bundled software, including estimated warranty costs, are recognized at the time of sale. Costs incurred to provide product-related bundled services and unspecified software upgrade rights are recognized as cost of sales as incurred. For certain long-term service arrangements, the Company has performance obligations for services it has not yet delivered. For these arrangements, the Company does not have a right to bill for the undelivered services. The Company has determined that any unbilled consideration relates entirely to the value of the undelivered services. Accordingly, the Company has not recognized revenue, and has elected not to disclose amounts, related to these undelivered services. For the sale of third-party products where the Company obtains control of the product before transferring it to the customer, the Company recognizes revenue based on the gross amount billed to customers. The Company considers multiple factors when determining whether it obtains control of third-party products including, but not limited to, evaluating if it has the ability to establish the price of the product, retains inventory risk for tangible products or has the responsibility for ensuring acceptability of the product. For third-party applications sold through the App Store, Mac App Store and TV App Store and certain digital content sold through the iTunes Store, the Company does not obtain control of the product before transferring it to the customer. Therefore, the Company accounts for such sales on a net basis by recognizing in services net sales only the commission it retains. The Company has elected to record revenue net of taxes collected from customers that are remitted to governmental authorities, with the collected taxes recorded within other current liabilities until remitted to the relevant government authority.
Marketable Securities	The Company’s investments in marketable debt 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. Unrealized gains and losses on marketable debt securities classified as available-for-sale are recognized in other comprehensive income/(loss) (“OCI”). The Company’s investments in mutual funds represent its only marketable equity securities and are classified as short-term based on the nature of the securities and their availability for use in current operations. The Company’s marketable equity securities are measured at fair value with gains and losses recognized in other income/(expense), net.
Fair Value Measurements	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.
Non-Marketable Securities	The Company holds non-marketable equity securities of certain privately held companies without readily determinable fair values, and has elected to apply the measurement alternative. As such, the Company’s non-marketable equity securities are measured at cost, less any impairment, and are adjusted for changes in fair value resulting from observable transactions for identical or similar investments of the same issuer. Gains and losses on non-marketable equity securities are recognized in other income/(expense), net.
Derivative Financial Instruments	The Company records all derivatives in the Condensed Consolidated Balance Sheets at fair value. The Company’s accounting treatment for these derivative instruments is based on its hedge designation. The Company classifies cash flows related to derivative financial instruments as operating activities in its Condensed Consolidated Statements of Cash Flows. 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 December 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 December 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 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 Condensed 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.
Segment Reporting	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” of the Notes to Consolidated Financial Statements in Part II, Item 8 of the 2018 Form 10-K. 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.