Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Summary of Weighted Average Asset Allocation of Plan Assets by Asset Category (Detail)

v3.4.0.3
Employee Benefit Plans - Summary of Weighted Average Asset Allocation of Plan Assets by Asset Category (Detail)
12 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]    
Target Plan Asset Allocations 100.00% 100.00%
Equity Securities [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Target Plan Asset Allocations Range Minimum 50.00%  
Target Plan Asset Allocations Range Maximum 70.00%  
Target Plan Asset Allocations 67.00% 66.00%
Debt Securities [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Target Plan Asset Allocations Range Minimum 20.00%  
Target Plan Asset Allocations Range Maximum 50.00%  
Target Plan Asset Allocations 33.00% 34.00%