FAIR VALUE MEASUREMENTS (Details) (USD $) In Thousands, unless otherwise specified							3 Months Ended		6 Months Ended
	Nov. 29, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]	May 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Nov. 29, 2011 Estimate of Fair Value, Fair Value Disclosure [Member]	May 31, 2011 Estimate of Fair Value, Fair Value Disclosure [Member]	Nov. 29, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	May 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Nov. 29, 2011 Fair Value, Measurements, Nonrecurring [Member]	Nov. 30, 2010 Fair Value, Measurements, Nonrecurring [Member]	Nov. 29, 2011 Fair Value, Measurements, Nonrecurring [Member]	Nov. 30, 2010 Fair Value, Measurements, Nonrecurring [Member]	Nov. 29, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		May 31, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan - Assets					$ 7,920	$ 8,792
Deferred compensation plan - Liabilities					(7,920)	(8,792)
Total					0	0
Long-lived assets held for sale											23,187	[1]	24,686	[1]
Long-lived assets held for use											839		747
Total											24,026		25,433
Long-lived assets held for sale included in construction in progress											20,700		23,300
Long-lived assets held for sale							0	0	206	989
Long-lived assets held for use							630	12	630	349
Total impairment of long-lived assets							630	12	836	1,338
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred Compensation Plan investment in RTI common stock	1,513	1,556	1,035	1,653
Long-term debt and capital leases	342,157	344,274	343,432	348,272
Letters of credit	$ 0	$ 0	$ 222	$ 178

[1] Included in the carrying value of long-lived assets held for sale as of November 29, 2011 and May 31, 2011 are $20.7 million and $23.3 million, respectively, of assets included in Construction in progress in the Condensed Consolidated Balance Sheets as we do not expect to sell these assets within the next 12 months.