Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Aug. 26, 2017	May 27, 2017	Feb. 25, 2017	Nov. 26, 2016	Aug. 27, 2016	May 28, 2016	Feb. 27, 2016	Nov. 28, 2015	Aug. 26, 2017	Aug. 27, 2016	Aug. 29, 2015
Condensed Income Statements, Captions [Line Items]
Revenues	$ 403,589	$ 409,834	$ 391,427	$ 386,108	$ 363,766	$ 367,799	$ 363,097	$ 373,384	$ 1,590,958	$ 1,468,046	$ 1,456,605
Income (loss) before income taxes	(7,677)	39,362	37,374	46,064	57,315	48,699	38,999	58,358	115,123	203,371	201,268
Provision (benefit) for income taxes	(2,781)	15,000	14,858	17,850	21,821	18,555	15,501	22,468	44,927	78,345	76,969
Net income (loss)	$ (4,896)	$ 24,362	$ 22,516	$ 28,214	35,494	$ 30,144	$ 23,498	$ 35,890	$ 70,196	$ 125,026	$ 124,299
Income (loss) per share – diluted
Common Stock (in dollars per share)									$ 3.44	$ 6.17	$ 6.15
Income (loss) allocated to – basic
Common Stock									$ 70,196	$ 125,026	$ 124,299
Income (loss) allocated to – diluted
Common Stock									$ 69,837	$ 124,409	$ 123,472
Weighted average number of shares outstanding – Basic:
Common Stock (in shares)									20,284	20,168	20,098
Weighted average number of shares outstanding – Diluted:
Common Stock (in shares)									20,276	20,154	20,079
Selling and Administrative Expenses
Weighted average number of shares outstanding – Diluted:
Gain related to environmental litigation settlement					$ 15,900
Benefit to diluted earnings per share (in dollars per share)					$ 0.48
Machinery and Equipment
Income (loss) per share – diluted
Common Stock (in dollars per share)	$ (1.68)
Income (loss) allocated to – diluted
Common Stock	$ (34,100)
Weighted average number of shares outstanding – Diluted:
Impairment charge of capitalized costs as part of ongoing CRM systems project	$ 55,800
Mr. Croatti | Restricted Stock Award Agreement
Income (loss) per share – diluted
Common Stock (in dollars per share)		$ (0.16)
Income (loss) allocated to – diluted
Common Stock		$ (3,300)
Weighted average number of shares outstanding – Diluted:
Pre-tax loss compensation expense as a result of accelerated vesting of certain shares		$ 5,400							$ 5,400
Common Stock
Income (loss) per share – basic
Common Stock (in dollars per share)	$ (0.25)	$ 1.26	$ 1.17	$ 1.46	1.84	$ 1.57	$ 1.23	$ 1.88	$ 3.63	$ 6.51	$ 6.50
Income (loss) per share – diluted
Common Stock (in dollars per share)	$ (0.24)	$ 1.19	$ 1.10	$ 1.38	$ 1.74	$ 1.49	$ 1.16	$ 1.78
Income (loss) allocated to – basic
Common Stock	$ (3,908)	$ 19,307	$ 17,836	$ 22,342	$ 28,097	$ 23,939	$ 18,691	$ 28,539	$ 55,903	$ 99,282	$ 98,665
Income (loss) allocated to – diluted
Common Stock	$ (4,886)	$ 24,199	$ 22,362	$ 28,020	$ 35,250	$ 30,007	$ 23,401	$ 35,741
Weighted average number of shares outstanding – Basic:
Common Stock (in shares)	15,402	15,326	15,305	15,285	15,268	15,253	15,241	15,218	15,382	15,245	15,182
Weighted average number of shares outstanding – Diluted:
Common Stock (in shares)	20,220	20,279	20,263	20,249	20,223	20,183	20,138	20,132
Class B Common Stock
Income (loss) per share – basic
Common Stock (in dollars per share)	$ (0.20)	$ 1.01	$ 0.93	$ 1.17	$ 1.47	$ 1.26	$ 0.98	$ 1.50	$ 2.91	$ 5.21	$ 5.20
Income (loss) allocated to – basic
Common Stock	$ (978)	$ 4,883	$ 4,518	$ 5,668	$ 7,139	$ 6,061	$ 4,704	$ 7,193	$ 13,915	$ 25,093	$ 24,761
Weighted average number of shares outstanding – Basic:
Common Stock (in shares)	4,818	4,846	4,846	4,847	4,850	4,827	4,795	4,795	4,786	4,816	4,763