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Weighted-Average Asset Allocation of Said Plan Assets for Pension Benefits (Detail) - Pension
Mar. 31, 2018
Funds managed by trust  
Weighted-average asset allocation 100.00%
Government Securities  
Funds managed by trust  
Weighted-average asset allocation 5.90%
Debenture and bonds  
Funds managed by trust  
Weighted-average asset allocation 78.90%
Other  
Funds managed by trust  
Weighted-average asset allocation 15.20%