Note 15 - Fair Value (Details) (USD $)	12 Months Ended			9 Months Ended	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012	Feb. 28, 2014 Geographic Concentration Risk [Member] UNITED STATES Cash and Cash Equivalents [Member]	May 31, 2014 Geographic Concentration Risk [Member] UNITED STATES Cash and Cash Equivalents [Member]	May 31, 2013 Geographic Concentration Risk [Member] UNITED STATES Cash and Cash Equivalents [Member]	May 31, 2014 LIFECODES [Member]	May 31, 2013 LIFECODES [Member]	Mar. 22, 2013 LIFECODES [Member]	May 30, 2014 Organ-i [Member]	May 31, 2014 Term Loan Facility [Member]	May 31, 2013 Term Loan Facility [Member]	May 31, 2014 Notes Payable, Other Payables [Member]	May 31, 2013 Notes Payable, Other Payables [Member]
Note 15 - Fair Value (Details) [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 23,621,000	$ 29,388,000	$ 18,578,000
Concentration Risk, Percentage				19.00%	19.00%	38.00%
Long-term Debt, Fair Value											656,700,000	669,100,000	446,300,000	452,300,000
Business Combination, Contingent Consideration, Liability	11,300,000	4,504,000					0	4,500,000	4,400,000	11,300,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	$ (4,638,000)	$ 104,000					$ (4,600,000)