Income Taxes	9 Months Ended
Income Taxes	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 13—Income Taxes The effective income tax rates were 19% for the three and nine months ended June 30, 2020, and 20% and 19% for the three and nine months ended June 30, 2019, respectively. The difference in the effective tax rates between the three-month periods was primarily due to the change in geographic mix of income. During the three and nine months ended June 30, 2020, the Company’s gross unrecognized tax benefits increased by $55 million and $230 million, respectively. The Company’s net unrecognized tax benefits that, if recognized, would favorably impact the effective tax rate, increased by $31 million and $70 million, respectively. The change in unrecognized tax benefits is primarily related to various tax positions across several jurisdictions. The Company’s accrued interest related to uncertain tax positions increased by $18 million and $56 million during the three and nine months ended June 30, 2020, respectively, and $19 million and $51 million during the three and nine months ended June 30, 2019, respectively. During the three and nine months ended June 30, 2020 and 2019, there were no significant changes in penalties related to uncertain tax positions. The Company’s tax filings are subject to examination by the U.S. federal, state and foreign taxing authorities. The timing and outcome of the final resolutions of the various ongoing income tax examinations are highly uncertain. It is not reasonably possible to estimate the increase or decrease in unrecognized tax benefits within the next twelve months. The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted in the U.S. on March 27, 2020. The CARES Act includes several U.S. income tax provisions related to, among other things, net operating loss carrybacks, alternative minimum tax credits, modifications to the net interest deduction limitations, and technical amendments regarding the income tax depreciation of qualified improvement property placed in service after December 31, 2017. The CARES Act is not expected to have a material impact on the Company’s financial results. On July 22, 2020, UK enacted a legislation that repealed the previous tax rate reduction from 19% to 17% that was effective on April 1, 2020. The repeal of the UK tax rate reduction is not expected to significantly increase the Company’s ongoing effective tax rate, however, it will result in a one-time non-cash tax expense in the fourth quarter of fiscal 2020, due to the re-measurement of deferred taxes which are primarily related to intangibles recorded in purchase accounting upon the acquisition of Visa Europe in fiscal 2016.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.