Commitments and Contingencies - Schedule of Future Insurance Proceeds (Detail) $ in Millions	Jun. 30, 2017 USD ($)
Loss Contingency, Estimated Insurance Recoveries [Abstract]
Loss Contingency, Estimated Insurance Recoveries	$ 25.0
Asbestos Issue [Member]
Loss Contingency, Estimated Insurance Recoveries [Abstract]
Loss Contingency, Receivable	34.0
Loss Contingency, Estimated Insurance Recoveries	4.6
Loss Contingency, Estimated Insurance Recoveries, Year Two	16.8
Loss Contingency, Estimated Insurance Recoveries, Year Three	5.9
Loss Contingency Estimated Insurance Recoveries Year Four	2.5
GST, LLC [Member] | Asbestos Issue [Member]
Loss Contingency, Estimated Insurance Recoveries [Abstract]
Loss Contingency, Insurance Coverage, Amount Recovered, Insolvent Carrier	$ 8.7