Business Segments - Business Segment Net Sales and (Loss) Income before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue from External Customer [Line Items]
Net sales	$ 127,427	$ 110,550	$ 242,504	$ 214,066
(Loss) income before Income Taxes	(2,152)	(2,336)	(1,204)	(6,913)
Operating Segments [Member]
Revenue from External Customer [Line Items]
Net sales	127,427	110,550	242,504	214,066
(Loss) income before Income Taxes	2,284	2,234	5,419	4,192
Operating Segments [Member] | Forged and Cast Engineered Products [Member]
Revenue from External Customer [Line Items]
Net sales	102,986	88,358	196,894	170,060
(Loss) income before Income Taxes	(1,464)	(446)	(588)	(1,169)
Operating Segments [Member] | Air and Liquid Processing [Member]
Revenue from External Customer [Line Items]
Net sales	24,441	22,192	45,610	44,006
(Loss) income before Income Taxes	3,748	2,680	6,007	5,361
Other Expense, Including Corporate Costs - Net [Member]
Revenue from External Customer [Line Items]
(Loss) income before Income Taxes	$ (4,436)	$ (4,570)	$ (6,623)	$ (11,105)