Business Segments - Business Segment Net Sales and (Loss) Income before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from External Customer [Line Items]
Net sales	$ 112,216	$ 103,886	$ 354,720	$ 317,952
(Loss) income before Income Taxes	(5,656)	(3,707)	(6,860)	(10,620)
Operating Segments [Member]
Revenue from External Customer [Line Items]
Net sales	112,216	103,886	354,720	317,952
(Loss) income before Income Taxes	(2,430)	949	2,989	5,141
Operating Segments [Member] | Forged and Cast Engineered Products [Member]
Revenue from External Customer [Line Items]
Net sales	88,090	81,679	284,984	251,739
(Loss) income before Income Taxes	(5,395)	(1,470)	(5,983)	(2,639)
Operating Segments [Member] | Air and Liquid Processing [Member]
Revenue from External Customer [Line Items]
Net sales	24,126	22,207	69,736	66,213
(Loss) income before Income Taxes	2,965	2,419	8,972	7,780
Other Expense, Including Corporate Costs - Net [Member]
Revenue from External Customer [Line Items]
(Loss) income before Income Taxes	$ (3,226)	$ (4,656)	$ (9,849)	$ (15,761)