Income Taxes (Details 5) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	Dec. 01, 2012
Deferred tax assets:
Deferred compensation	$ 7,945	$ 9,925
Loss carryforward and tax credit items	2,529	2,603
Accounts receivable	5,973	5,911
Inventories	5,000	5,062
Pensions	4,781	26,222
Accrued liabilities and other	1,219	1,403
Valuation allowance	(1,102)	(1,911)
Total deferred tax assets, net	26,345	49,215
Deferred tax liabilities:
Percentage of completion	(539)	(366)
Plant assets	(24,182)	(25,708)
Goodwill and acquired intangible assets	(40,380)	(39,431)
Other deferred tax liabilities	(345)	(402)
Total deferred tax liabilities	(65,446)	(65,907)
Deferred tax liability, net	$ (39,101)	$ (16,692)