Comprehensive Income (Loss) Changes in AOCI by component (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2015	Mar. 01, 2014	Feb. 28, 2015	Mar. 01, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	$ (2,409)	$ 364	$ (1,808)	$ 849
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	944	2,234	944	2,385
Amounts reclassified from AOCI	(602)	(708)	(1,203)	(1,344)
Net current-period OCI	342	1,526	(259)	1,041
Balance at end of period	(2,067)	1,890	(2,067)	1,890
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(2,409)	364	(1,808)	1,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	944	2,234	944	2,234
Amounts reclassified from AOCI	(602)	(708)	(1,203)	(1,344)
Net current-period OCI	342	1,526	(259)	890
Balance at end of period	(2,067)	1,890	(2,067)	1,890
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	0	0	0	(151)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	0	0	0	151
Amounts reclassified from AOCI	0	0	0	0
Net current-period OCI	0	0	0	151
Balance at end of period	$ 0	$ 0	$ 0	$ 0