XML 115 R91.htm IDEA: XBRL DOCUMENT v2.4.0.8
One-Percentage Rate Change in Assumed Health Care Cost Trend Rates and Its Effects on Accumulated Postretirement Benefit Obligation (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Mar. 31, 2014
Schedule of Pension Expected Future Benefit Payments [Line Items]  
Defined benefit plan, effect of one percentage point increase on accumulated postretirement benefit obligation $ 3,232
Defined benefit plan, effect of one percentage point increase on aggregate service and interest cost 222
Defined benefit plan, effect of one percentage point decrease on accumulated postretirement benefit obligation 2,664
Defined benefit plan, effect of one percentage point decrease on aggregate service and interest cost $ 179