Pension and Postretirement Benefits (Details) (USD $) In Millions	3 Months Ended
	Aug. 28, 2011	Aug. 29, 2010
Pension Benefits [Member]
Components of pension benefit and other postretirement benefit costs
Service cost	$ 17.1	$ 14.9
Interest cost	37.2	36.9
Expected return on plan assets	(44.9)	(43.3)
Amortization of prior service cost (gain)	0.8	0.8
Recognized net actuarial loss	9.6	4.1
Curtailment loss		1.3
Benefit cost - Company plans	19.8	14.7
Pension benefit cost - multi-employer plans	2.1	2.5
Total benefit cost	21.9	17.2
Pension and Postretirement Benefits (Textuals) [Abstract]
Employer contributions to pension plan and other postretirement plan	3.0
Further contribution to pension and other postretirement plan.	79.2
Postretirement Benefits [Member]
Components of pension benefit and other postretirement benefit costs
Service cost	0.2	0.1
Interest cost	3.7	4.1
Expected return on plan assets		(0.1)
Amortization of prior service cost (gain)	(2.2)	(2.4)
Recognized net actuarial loss	1.5	1.2
Benefit cost - Company plans	3.2	2.9
Total benefit cost	3.2	2.9
Pension and Postretirement Benefits (Textuals) [Abstract]
Employer contributions to pension plan and other postretirement plan	7.5
Further contribution to pension and other postretirement plan.	$ 21.0