Restructuring (Tables)

6 Months Ended

Oct. 31, 2013

Restructuring [Abstract]

Restructuring and related charges

	Long-Lived Asset Charges		Employee Separation		Site Preparation and Equipment Relocation		Production Start-up		Other Costs		Total
Total expected restructuring charge	$	102.0	$	67.0	$	42.5	$	39.0	$	9.5	$	260.0
Balance at May 1, 2012	$	—	$	8.8	$	—	$	—	$	—	$	8.8
Charge to expense		8.2		3.4		13.4		10.8		3.0		38.8
Cash payments		—		(4.5)		(13.4)		(10.8)		(3.0)		(31.7)
Noncash utilization		(8.2)		—		—		—		—		(8.2)
Balance at April 30, 2013	$	—	$	7.7	$	—	$	—	$	—	$	7.7
Charge to expense		1.7		2.5		3.9		3.4		0.5		12.0
Cash payments		—		(2.1)		(3.9)		(3.4)		(0.5)		(9.9)
Noncash utilization		(1.7)		(0.2)		—		—		—		(1.9)
Balance at October 31, 2013	$	—	$	7.9	$	—	$	—	$	—	$	7.9
Remaining expected restructuring charge	$	0.4	$	3.6	$	5.6	$	9.0	$	1.8	$	20.4