Fair Value - Summary Showing the Recurring Fair Value Measurements of the Contingent Consideration Liability (Detail) (USD $) In Thousands, unless otherwise specified					9 Months Ended			9 Months Ended
	Feb. 28, 2014	May 31, 2013	Feb. 28, 2014 Level 3 [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Revenue Based Payments [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Revenue Based Payments [Member] Minimum [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Revenue Based Payments [Member] Maximum [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Milestone Based Payments [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Milestone Based Payments [Member] Minimum [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]	Feb. 28, 2014 Level 3 [Member] Milestone Based Payments [Member] Maximum [Member] Recurring [Member] Contingent Consideration Earn Out Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Revenue based payments	$ 67,987	$ 75,049	$ 67,987	$ 63,487			$ 4,500
Discount rate					4.00%	10.00%		16.00%	20.00%
Probability of payment					75.00%	100.00%		75.00%	100.00%
Projected fiscal year of payment					2014	2022		2014	2015