Stock Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Aug. 31, 2019	Sep. 01, 2018	Jun. 01, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense (benefit)	$ 890	$ 903
Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 5,100
Weighted average period of unrecognized compensation expense (in years)	1 year 10 months 24 days
Number of options outstanding (in shares)	246,561
Weighted average grant date fair value (in dollars per share)	$ 43.20		$ 43.20

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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