Contingencies - Additional Information (Detail) - RTI Technologies - USD ($) $ in Millions				3 Months Ended		9 Months Ended
	Jan. 15, 2015	Sep. 19, 2013	Nov. 09, 2009	Dec. 31, 2016	Sep. 30, 2013	Jun. 30, 2017
Loss Contingencies [Line Items]
Damages awarded	$ 341.0	$ 113.5	$ 5.0
Pre-tax charge relating to an unfavorable litigation verdict					$ 341.0
Professional fees	$ (12.0)			$ 336.0		$ 336.0