Business And Summary Of Significant Accounting Policies (Narrative) (Details)		1 Months Ended			12 Months Ended
		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 portion of $21,815 for operating leases and $1,262 for finance leases