Comprehensive Income (Loss) Changes in AOCI by component (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May. 30, 2015	May. 31, 2014	May. 30, 2015	May. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	$ (2,067)	$ 1,890	$ (1,808)	$ 849
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	0	0	944	2,385
Amounts reclassified from AOCI	(654)	(752)	(1,857)	(2,096)
Net current-period OCI	(654)	(752)	(913)	289
Balance at end of period	(2,721)	1,138	(2,721)	1,138
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(2,067)	1,890	(1,808)	1,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	0	0	944	2,234
Amounts reclassified from AOCI	(654)	(752)	(1,857)	(2,096)
Net current-period OCI	(654)	(752)	(913)	138
Balance at end of period	(2,721)	1,138	(2,721)	1,138
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