Income Taxes	6 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the U.S. enacted the Tax Cuts and Jobs Act (the “Act”), which significantly changed U.S. tax law. The Act lowered the Company’s U.S. statutory federal income tax rate from 35% to 21% effective January 1, 2018, while also imposing a deemed repatriation tax on previously deferred foreign income. The Act also created a new minimum tax on certain future foreign earnings. During the first six months of fiscal 2018, the Company recognized income tax expense of $9.3 billion, of which $2.6 billion was a provisional estimate in accordance with the U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 118 and was recognized during the first quarter of 2018. This $2.6 billion provisional estimate included $1.8 billion related to the impact of remeasuring to reduce the Company’s deferred tax balances to reflect the new tax rate, and approximately $800 million associated with the net impact of the deemed repatriation tax. Deferred Tax Balances As a result of the Act, the Company remeasured certain deferred tax assets and liabilities based on the revised rates at which they are expected to reverse, including items for which the related income tax effects were originally recognized in OCI. In addition, the Company elected to record certain deferred tax assets and liabilities related to the new minimum tax on certain future foreign earnings. The provisional estimate of $1.8 billion noted above incorporates assumptions based upon the best available interpretation of the Act and may change as the Company receives additional clarification and implementation guidance. 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 at the beginning of the second quarter of 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 Condensed Consolidated Balance Sheet. Deemed Repatriation Tax As of September 30, 2017, the Company had a U.S. deferred tax liability of $36.4 billion for deferred foreign income. As a result of the deemed repatriation tax, which is based on the Company’s cumulative post-1986 deferred foreign income, the Company replaced $36.1 billion of its U.S. deferred tax liability with a provisional tax payable of $38.0 billion. This estimate of the deemed repatriation tax is based, in part, on the amount of cash and other specified assets anticipated to be held by the Company’s foreign subsidiaries as of September 29, 2018. Therefore, the tax payable may change as the asset amounts are finalized. The Company plans to pay the tax in installments in accordance with the Act. Unrecognized Tax Benefits As of March 31, 2018, the Company had gross unrecognized tax benefits of $9.5 billion. These gross unrecognized tax benefits have been offset by certain tax deposits and a $1.1 billion reduction for the estimated impact of the deemed repatriation tax, with the net unrecognized tax benefits classified as other non-current liabilities in the Condensed Consolidated Balance Sheet. Upon recognition, $8.2 billion of the unrecognized tax benefits would impact the Company’s effective tax rate. The Company had accrued $1.5 billion of gross interest and penalties as of March 31, 2018, which are also classified as other non-current liabilities in the Condensed Consolidated Balance Sheet. The Company believes that an adequate provision has been made for any adjustments that may result from tax examinations. However, the outcome of tax audits cannot be predicted with certainty. If any issues addressed in the Company’s tax audits are resolved in a manner inconsistent with its expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs. Although timing of resolution and/or closure of audits is not certain, the Company believes it is reasonably possible that its gross unrecognized tax benefits could decrease (either by payment, release or a combination of both) in the next 12 months by as much as $3.4 billion. European Commission State Aid Decision On August 30, 2016, the European Commission announced its decision that Ireland granted state aid to the Company by providing tax opinions in 1991 and 2007 concerning the tax allocation of profits of the Irish branches of two subsidiaries of the Company (the “State Aid Decision”). The State Aid Decision orders Ireland to calculate and recover additional taxes from the Company for the period June 2003 through December 2014. Irish legislative changes, effective as of January 2015, eliminated the application of the tax opinions from that date forward. The Company believes the State Aid Decision to be without merit and appealed to the General Court of the Court of Justice of the European Union. Ireland has also appealed the State Aid Decision. Although Ireland is still computing the recovery amount, the Company expects the amount to be in line with the European Commission’s announced recovery amount of €13 billion, plus interest of €1 billion. During the third quarter of 2018, the Company expects to begin funding amounts into escrow, where they will remain pending conclusion of all appeals. The Company believes that any incremental Irish corporate income taxes potentially due related to the State Aid Decision would be creditable against U.S. taxes.

Income Taxes

On December 22, 2017, the U.S. enacted the Tax Cuts and Jobs Act (the “Act”), which significantly changed U.S. tax law. The Act lowered the Company’s U.S. statutory federal income tax rate from 35% to 21% effective January 1, 2018, while also imposing a deemed repatriation tax on previously deferred foreign income. The Act also created a new minimum tax on certain future foreign earnings. During the first six months of fiscal 2018, the Company recognized income tax expense of $9.3 billion, of which $2.6 billion was a provisional estimate in accordance with the U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 118 and was recognized during the first quarter of 2018. This $2.6 billion provisional estimate included $1.8 billion related to the impact of remeasuring to reduce the Company’s deferred tax balances to reflect the new tax rate, and approximately $800 million associated with the net impact of the deemed repatriation tax.

Deferred Tax Balances

As a result of the Act, the Company remeasured certain deferred tax assets and liabilities based on the revised rates at which they are expected to reverse, including items for which the related income tax effects were originally recognized in OCI. In addition, the Company elected to record certain deferred tax assets and liabilities related to the new minimum tax on certain future foreign earnings. The provisional estimate of $1.8 billion noted above incorporates assumptions based upon the best available interpretation of the Act and may change as the Company receives additional clarification and implementation guidance.

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 at the beginning of the second quarter of 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 Condensed Consolidated Balance Sheet.

Deemed Repatriation Tax

As of September 30, 2017, the Company had a U.S. deferred tax liability of $36.4 billion for deferred foreign income. As a result of the deemed repatriation tax, which is based on the Company’s cumulative post-1986 deferred foreign income, the Company replaced $36.1 billion of its U.S. deferred tax liability with a provisional tax payable of $38.0 billion. This estimate of the deemed repatriation tax is based, in part, on the amount of cash and other specified assets anticipated to be held by the Company’s foreign subsidiaries as of September 29, 2018. Therefore, the tax payable may change as the asset amounts are finalized. The Company plans to pay the tax in installments in accordance with the Act.

Unrecognized Tax Benefits

As of March 31, 2018, the Company had gross unrecognized tax benefits of $9.5 billion. These gross unrecognized tax benefits have been offset by certain tax deposits and a $1.1 billion reduction for the estimated impact of the deemed repatriation tax, with the net unrecognized tax benefits classified as other non-current liabilities in the Condensed Consolidated Balance Sheet. Upon recognition, $8.2 billion of the unrecognized tax benefits would impact the Company’s effective tax rate. The Company had accrued $1.5 billion of gross interest and penalties as of March 31, 2018, which are also classified as other non-current liabilities in the Condensed Consolidated Balance Sheet.

The Company believes that an adequate provision has been made for any adjustments that may result from tax examinations. However, the outcome of tax audits cannot be predicted with certainty. If any issues addressed in the Company’s tax audits are resolved in a manner inconsistent with its expectations, the Company could be required to adjust its provision for income taxes in the period such resolution occurs. Although timing of resolution and/or closure of audits is not certain, the Company believes it is reasonably possible that its gross unrecognized tax benefits could decrease (either by payment, release or a combination of both) in the next 12 months by as much as $3.4 billion.

European Commission State Aid Decision

On August 30, 2016, the European Commission announced its decision that Ireland granted state aid to the Company by providing tax opinions in 1991 and 2007 concerning the tax allocation of profits of the Irish branches of two subsidiaries of the Company (the “State Aid Decision”). The State Aid Decision orders Ireland to calculate and recover additional taxes from the Company for the period June 2003 through December 2014. Irish legislative changes, effective as of January 2015, eliminated the application of the tax opinions from that date forward. The Company believes the State Aid Decision to be without merit and appealed to the General Court of the Court of Justice of the European Union. Ireland has also appealed the State Aid Decision. Although Ireland is still computing the recovery amount, the Company expects the amount to be in line with the European Commission’s announced recovery amount of €13 billion, plus interest of €1 billion. During the third quarter of 2018, the Company expects to begin funding amounts into escrow, where they will remain pending conclusion of all appeals. The Company believes that any incremental Irish corporate income taxes potentially due related to the State Aid Decision would be creditable against U.S. taxes.