Commitments and Contingencies - Additional Information (Detail) $ in Millions	Mar. 31, 2017 USD ($) LegalMatter	Dec. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number | LegalMatter	3,300
Environmental Reserve Other Accrued Costs	$ 17.6	$ 18.3
Letters of credit outstanding	$ 353.9	331.0
Valves And Controls [Member]
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number | LegalMatter	2,800
Liability For Claims And Contingencies	$ 224.6	228.3
Liability Reserve For Insurance Claims	107.4	108.5
Letters of credit outstanding	$ 149.1	$ 156.6