Comprehensive Income Changes in AOCI by component (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2013	Dec. 01, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	$ 849	$ (3,686)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	151	(1)
Amounts reclassified from AOCI	(636)	(481)
Net current-period OCI	(485)	(482)
Balance at end of period	364	(4,168)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	1,000	(3,326)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	0	0
Amounts reclassified from AOCI	(636)	(481)
Net current-period OCI	(636)	(481)
Balance at end of period	364	(3,807)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	(151)	(360)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
OCI before reclassifications	151	(1)
Amounts reclassified from AOCI	0	0
Net current-period OCI	151	(1)
Balance at end of period	$ 0	$ (361)