Guarantees and Contingencies - Additional Information (Detail) - USD ($)			1 Months Ended	3 Months Ended
	Jan. 18, 2017	Mar. 04, 2016	Mar. 31, 2014	Sep. 30, 2017	Mar. 31, 2017
Lower Passaic River
Loss Contingencies [Line Items]
Estimated remediation cost		$ 1,380,000,000
Gowanus Canal Superfund Site
Loss Contingencies [Line Items]
Estimated remediation cost			$ 506,000,000
Facilities in North Dakota
Loss Contingencies [Line Items]
Penalty assessed under consent decree	$ 922,000
Initial penalty payment under consent decree					$ 55,000
Consent decree penalty paid				$ 745,000