Income Taxes	9 Months Ended
May 12, 2013
Income Tax Disclosure [Abstract]
Income Taxes	Note 7—Income Taxes The Company’s reported effective income tax rates for the twelve and thirty-six weeks ended May 12, 2013, were 34.8% and 31.4%, respectively, compared to 34.8% and 36.4% for the twelve and thirty-six weeks ended May 6, 2012, respectively, in the accompanying condensed consolidated statements of income, which includes the net impact of discrete tax items. The current year effective tax rate was favorably impacted by discrete tax benefits of $72, primarily due to a $62 tax deduction recorded in the second quarter in connection with the special cash dividend paid by the Company to employees through the Company’s 401(k) Retirement Plan. The Company’s effective tax rate for the first thirty-six weeks of 2012 was adversely impacted by a net discrete expense of $23 relating primarily to the adverse impact of an audit of Costco Mexico by the Mexican tax authority and the tax effects of nondeductible expenses for the Company’s contributions to an initiative reforming alcohol beverage laws in Washington State.

Income Taxes

9 Months Ended

May 12, 2013

Note 7—Income Taxes

The Company’s reported effective income tax rates for the twelve and thirty-six weeks ended May 12, 2013, were 34.8% and 31.4%, respectively, compared to 34.8% and 36.4% for the twelve and thirty-six weeks ended May 6, 2012, respectively, in the accompanying condensed consolidated statements of income, which includes the net impact of discrete tax items. The current year effective tax rate was favorably impacted by discrete tax benefits of $72, primarily due to a $62 tax deduction recorded in the second quarter in connection with the special cash dividend paid by the Company to employees through the Company’s 401(k) Retirement Plan.

The Company’s effective tax rate for the first thirty-six weeks of 2012 was adversely impacted by a net discrete expense of $23 relating primarily to the adverse impact of an audit of Costco Mexico by the Mexican tax authority and the tax effects of nondeductible expenses for the Company’s contributions to an initiative reforming alcohol beverage laws in Washington State.