Quarterly report pursuant to Section 13 or 15(d)

Changes in Each Component of Accumulated Other Comprehensive Income (Loss) (Detail)

v3.3.1.900
Changes in Each Component of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Oct. 31, 2015
Oct. 31, 2014
Oct. 31, 2015
Oct. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income (loss), beginning balance $ (55,812) $ (5,587) $ (40,623) $ (2,388)
Unrealized (losses) gains arising during the period (1,351) (12,551) (16,987) (16,237)
Reclassification of realized net losses (gains) to net income 448 467 895 954
Accumulated other comprehensive income (loss), ending balance (56,715) (17,671) (56,715) (17,671)
Accumulated Translation Adjustment        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income (loss), beginning balance (36,551) 11,924 (20,919) 15,604
Unrealized (losses) gains arising during the period (1,351) (12,555) (16,983) (16,235)
Accumulated other comprehensive income (loss), ending balance (37,902) (631) (37,902) (631)
Accumulated Defined Benefit Plans Adjustment        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income (loss), beginning balance (19,261) [1] (17,519) [2] (19,708) [1] (18,006) [2]
Reclassification of realized net losses (gains) to net income 448 [1] 467 [2] 895 [1] 954 [2]
Accumulated other comprehensive income (loss), ending balance $ (18,813) [1] (17,052) [2] (18,813) [1] (17,052) [2]
Accumulated Net Unrealized Investment Gain (Loss)        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Accumulated other comprehensive income (loss), beginning balance   8 4 14
Unrealized (losses) gains arising during the period   4 $ (4) (2)
Accumulated other comprehensive income (loss), ending balance   $ 12   $ 12
[1] The tax effects on the reclassifications of realized net losses was $0.3 million and $0.6 million for the three and six months ended October 31, 2015, respectively.
[2] The tax effects on the reclassifications of realized net losses was $0.3 million and $0.6 million for the three and six months ended October 31, 2014, respectively.