Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($) Person	Dec. 31, 2017 USD ($) Person	Dec. 31, 2016 USD ($) Person	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Significant Accounting Policies
Unamortized Debt Issuance Expense	$ 17,800,000	$ 6,800,000	$ 17,800,000
Impairment of Long-Lived Assets Held-for-use				$ 5,100,000
Revenue Recognition
Cost in excess of billings	107,700,000	121,400,000	107,700,000
Billings in excess of cost	22,500,000	29,900,000	22,500,000
Research and development
Research and development		$ 115,800,000	114,100,000	98,700,000
Goodwill and identifiable intangible assets
Goodwill planning period		6 years
Perpetual growth rate		3.00%
Discounted cash flows discount rate		9.00%
Impairment charges, related to trade names	13,300,000				$ 0
Insurance subsidiary
Reserve for policy claims	63,000,000	$ 61,500,000	63,000,000
Other Current Liabilities
Insurance subsidiary
Reserve for policy claims	13,200,000	13,200,000	13,200,000
Other Noncurrent Liabilities
Insurance subsidiary
Reserve for policy claims	$ 49,800,000	$ 48,300,000	$ 49,800,000
Valves And Controls [Member]
Goodwill and identifiable intangible assets
Goodwill, Impairment Loss				515,200,000
Impairment charges, related to trade names				$ 39,500,000
Credit Concentration Risk
Trade receivables and concentration of credit risk
Customer receivable balances to total trade receivables		10.00%	10.00%
Number of customers | Person	0	0	0
Minimum
Basis of presentation
Equity method investment, ownership percentage		20.00%
Maximum
Basis of presentation
Equity method investment, ownership percentage		50.00%