Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.20.1
Commitments and Contingencies - Additional Information (Detail)
Mar. 31, 2020
claim
Mar. 31, 2019
claim
Mar. 31, 2018
claim
Mar. 31, 2017
claim
Mar. 31, 2016
claim
Mar. 31, 2015
claim
Loss Contingencies [Line Items]            
Loss Contingency, Pending Claims, Number 393 332 336 352 426 494
New Zealand | Subsidiaries [Member] | New Zealand Weathertightness [Member]            
Loss Contingencies [Line Items]            
Loss Contingency, Pending Claims, Number         4