Pension and Savings Plans - Weighted Average Asset Allocation for Pension Plan Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 25, 2012	Aug. 27, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	$ 208,120	$ 181,409	$ 156,883
Asset allocation actual	100.00%	100.00%
Asset allocation target	100.00%	100.00%
U.S. Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	57,931	51,101
Asset allocation actual	27.90%	28.20%
Asset allocation target	30.00%	30.00%
International Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	38,145	31,767
Asset allocation actual	18.30%	17.50%
Asset allocation target	20.00%	20.00%
Emerging Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	19,030	16,471
Asset allocation actual	9.10%	9.10%
Asset allocation target	10.00%	10.00%
High Yield Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	19,858	17,378
Asset allocation actual	9.50%	9.60%
Asset allocation target	10.00%	10.00%
Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	1,226	2,404
Asset allocation actual	0.60%	1.30%
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	59,500	47,667
Asset allocation actual	28.60%	26.30%
Asset allocation target	30.00%	30.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	12,430	14,621
Asset allocation actual	6.00%	8.00%
Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | U.S. Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | International Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | Emerging Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | High Yield Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value
Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	206,894	179,005
Level 2 [Member] | U.S. Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	57,931	51,101
Level 2 [Member] | International Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	38,145	31,767
Level 2 [Member] | Emerging Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	19,030	16,471
Level 2 [Member] | High Yield Equities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	19,858	17,378
Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	59,500	47,667
Level 2 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	12,430	14,621
Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	1,226	2,404
Level 3 [Member] | Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Asset allocation fair value	$ 1,226	$ 2,404