RETIREMENT BENEFITS (Details) (USD $)	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Feb. 28, 2012	May 31, 2011	Feb. 28, 2012 Pension Plans, Defined Benefit [Member]	Mar. 01, 2011 Pension Plans, Defined Benefit [Member]	Feb. 28, 2012 Pension Plans, Defined Benefit [Member]	Mar. 01, 2011 Pension Plans, Defined Benefit [Member]	Feb. 28, 2012 Postretirement Medical and Life Benefits [Member]	Mar. 01, 2011 Postretirement Medical and Life Benefits [Member]	Feb. 28, 2012 Postretirement Medical and Life Benefits [Member]	Mar. 01, 2011 Postretirement Medical and Life Benefits [Member]
RETIREMENT BENEFITS [Abstract]
Defined benefit pension plans	3
Estimated contributions to be made in remainder of fiscal year	$ 200,000
Lump sum pension payment accrued liability for CEO	8,100,000
Time following retirement before payment is to be made (in months)	6M
Defined contribution plans		2
Defined Benefit Plan Disclosure [Line Items]
Service cost			134,000	129,000	402,000	387,000	2,000	2,000	6,000	6,000
Interest cost			576,000	573,000	1,728,000	1,719,000	18,000	19,000	54,000	57,000
Expected return on plan assets			(126,000)	(98,000)	(378,000)	(294,000)
Amortization of prior service cost			64,000	82,000	192,000	246,000	(14,000)	(15,000)	(42,000)	(45,000)
Recognized actuarial loss			426,000	398,000	1,278,000	1,194,000	34,000	28,000	102,000	84,000
Net periodic benefit cost			$ 1,074,000	$ 1,084,000	$ 3,222,000	$ 3,252,000	$ 40,000	$ 34,000	$ 120,000	$ 102,000