Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	Feb. 27, 2021	Nov. 28, 2020	May 30, 2020	Feb. 29, 2020	Nov. 30, 2019	Jun. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for doubtful accounts	$ 728		$ 744
Stockholders' equity	1,016,449	$ 1,004,710	1,009,675	$ 948,032	$ 934,293	$ 989,806
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity	$ 980,212	$ 968,325	975,147	$ 914,234	$ 900,485	$ 954,527
Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity			422
Adjustment [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity			$ 422