Restructuring Charges Related to Consolidation of Operations (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
May. 31, 2015
May. 31, 2014
May. 31, 2015
May. 31, 2014
Nov. 30, 2012
Restructuring Cost and Reserve [Line Items]          
Restructuring charges $ 840 $ 748 $ 1,670 $ 866  
EMS Restructuring          
Restructuring Cost and Reserve [Line Items]          
Restructuring charges         $ 591
Inventory write-down         7,401
Fixed asset impairment         865
Lease impairment         3,672
Accumulated restructuring charges         $ 12,529
Cash payments     (591)    
Non-cash charges     (10,124)    
Balance - Lease impairment accrual $ 1,814   $ 1,814