Schedule of Other Changes in Plan Assets and Benefit Obligation Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Plans, Defined Benefit
Schedule Of Accumulated Benefit Obligations In Excess Of Fair Value Of Plan Assets And Amounts Recognized In Balance Sheet And In Other Comprehensive Income Loss [Line Items]
Net (gain) loss	$ (343)	$ 8,621
Settlement loss	0	0
Amortization of prior service cost	(36)	(50)
Recognized actuarial (gain)	(2,269)	(988)
Total recognized in other comprehensive (income) loss, before tax	(2,648)	7,583
Net of tax	(1,721)	7,583
Other Pension Plans, Defined Benefit
Schedule Of Accumulated Benefit Obligations In Excess Of Fair Value Of Plan Assets And Amounts Recognized In Balance Sheet And In Other Comprehensive Income Loss [Line Items]
Net (gain) loss	(2,592)	(932)
Settlement loss	0	0
Amortization of prior service cost	2,996	2,032
Recognized actuarial (gain)	1,040	1,299
Prior service (cost) credit arising during period	(15,961)
Total recognized in other comprehensive (income) loss, before tax	(14,517)	2,399
Net of tax	$ (9,436)	$ 1,559