Fair Value - Fair Value Measurements Using Significant Unobservable Inputs (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, begining balance	$ 1,809
Earnings revaluation expense - included in earnings, assets	0
Included in other comprehensive income, assets	139
Contingent consideration - Clinical Devices, assets	0
Financial assets, ending balance	1,670
Financial liabilities, begining balance	67,331
Earnings revaluation expense - included in earnings, liabilities	801
Included in other comprehensive income, liabilities	0
Financial liabilities, ending balance	66,032
Clinical Devices B.V [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration - Clinical Devices, liabilities	$ (2,100)