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Business And Summary Of Significant Accounting Policies (Narrative) (Details) | 1 Months Ended | 12 Months Ended |
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Nov. 30, 2018 $ / shares | Oct. 31, 2018 $ / shares | Sep. 30, 2018 $ / shares | Aug. 29, 2020 USD ($) warehouse segment store | Aug. 31, 2019 USD ($) | Sep. 01, 2018 USD ($) | Sep. 01, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Number of branch offices | store |  |  |  |  | 98 |  |  |
Number of customer fulfillment centers | warehouse |  |  |  |  | 12 |  |  |
Cash equivalents |  |  |  |  | $ 0 | $ 0 |  |
Amortization expense |  |  |  |  | 11,463,000 | 11,746,000 | $ 10,513,000 |
Impairment loss |  |  |  |  | 0 | 0 | 0 |
Deferred principal catalog costs |  |  |  |  | $ 422,000 | 3,363,000 |  |
Period deferred principal catalog costs remain the most current source of sales |  |  |  |  | 1 year |  |  |
Advertising costs |  |  |  |  | $ 13,341,000 | 18,812,000 | 15,530,000 |
Shipping and handling costs |  |  |  |  | 125,859,000 | 138,242,000 | 130,340,000 |
Purchases of treasury stock |  |  |  |  | 3,444,000 | 84,611,000 | $ 82,369,000 |
Unrecognized tax benefit that would affect effective tax rate |  |  |  |  | $ 10,995,000 | $ 11,698,000 |  |
Number of Operating Segments | segment |  |  |  |  | 1 |  |  |
Number of reportable segments | segment |  |  |  |  | 1 |  |  |
Operating lease assets |  |  |  |  | $ 56,173,000 |  |  |
Operating lease liabilities | [1] |  |  |  | $ 56,194,000 |  |  |
Class A Common Stock [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Cost of repurchase, per share | $ / shares |  | $ 81.22 | $ 85.00 | $ 84.29 |  |  |  |
Accounting Standards Update 2016-02 [Member] | Restatement Adjustment [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Operating lease assets |  |  |  |  |  |  |  | $ 61,212,000
Operating lease liabilities |  |  |  |  |  |  |  | $ 60,730,000
Minimum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Original manufacturers warranty period |  |  |  |  | 30 days |  |  |
Maximum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Warranty period |  |  |  |  | 1 year |  |  |
Original manufacturers warranty period |  |  |  |  | 90 days |  |  |
Net Sales [Member] | Geographic Concentration Risk [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Concentration risk, percentage |  |  |  |  | 100.00% | 100.00% |  |
Net Sales [Member] | Geographic Concentration Risk [Member] | U.K., Canada, and Mexico [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Concentration risk, percentage |  |  |  |  | 5.00% |  |  |
Leasehold Improvements And Buildings [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 3 years |  |  |
Leasehold Improvements And Buildings [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 40 years |  |  |
Computer Systems, Equipment And Software [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 3 years |  |  |
Computer Systems, Equipment And Software [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 10 years |  |  |
Furniture, Fixtures And Equipment [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 3 years |  |  |
Furniture, Fixtures And Equipment [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Property, plant and equipment estimated useful life |  |  |  |  | 20 years |  |  |
Trademarks [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Impairment of intangible assets |  |  |  |  | $ 443,000 | $ 107,000 |  |
Customer Relationships And Trademarks [Member] |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |
Impairment of intangible assets |  |  |  |  |  | $ 6,200,000 |  |
[1] | Includes the current p ortion of $21,815 for operating leases and $1,262 for finance leases

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