Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Aug. 31, 2012	May 31, 2012
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 1,257.0	$ 1,134.8
Accumulated depreciation	(588.8)	(541.2)
Total property, plant and equipment, net	668.2	593.6
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	40.4	40.2
Buildings and leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	92.8	89.9
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	373.3	342.3
Instruments [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	717.6	633.3
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 32.9	$ 29.1