Pension and Postretirement Benefits (Tables)

9 Months Ended

Feb. 26, 2012

Pension and Postretirement Benefits [Abstract]

Components of pension benefit and other postretirement benefit costs

	Pension Benefits
	Thirteen weeks ended						Thirty-nine weeks ended
	February 26, 2012			February 27, 2011			February 26, 2012			February 27, 2011
Service cost	$	17.2		$	14.9		$	51.4		$	44.7
Interest cost		37.2			36.8			111.6			110.6
Expected return on plan assets		(44.9	)		(43.2	)		(134.7	)		(129.8	)
Amortization of prior service cost		0.8			0.8			2.3			2.4
Curtailment loss		—			0.1			—			1.4
Recognized net actuarial loss		9.6			4.1			28.9			12.3
Benefit cost — Company plans		19.9			13.5			59.5			41.6
Pension benefit cost — multi-employer plans		1.7			2.5			6.6			7.6
Total benefit cost	$	21.6		$	16.0		$	66.1		$	49.2

	Postretirement Benefits
	Thirteen weeks ended						Thirty-nine weeks ended
	February 26, 2012			February 27, 2011			February 26, 2012			February 27, 2011
Service cost	$	0.1		$	0.2		$	0.4		$	0.5
Interest cost		3.1			4.0			10.0			12.1
Expected return on plan assets		—			—			—			(0.1	)
Amortization of prior service cost		(3.9	)		(2.5	)		(9.7	)		(7.2	)
Recognized net actuarial loss		2.1			1.2			5.6			3.5
Total cost	$	1.4		$	2.9		$	6.3		$	8.8