Revenue and Income Before Income Taxes - Net Sales and Income Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Line Items]
Net sales	$ 102,582	$ 92,428	$ 197,008	$ 179,228
Income before income taxes	911	2,596	2,576	3,291
Forged and Cast Mill Rolls [Member]
Disaggregation Of Revenue [Line Items]
Net sales	66,586	65,974	127,293	124,140
Forged Engineered Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	12,992	5,054	27,044	10,239
Centrifugal Pumps [Member]
Disaggregation Of Revenue [Line Items]
Net sales	7,744	8,000	15,044	18,042
Air Handling Systems [Member]
Disaggregation Of Revenue [Line Items]
Net sales	7,067	7,502	13,676	14,852
Heat Exchange Coils [Member]
Disaggregation Of Revenue [Line Items]
Net sales	8,193	5,898	13,951	11,955
U.S. [Member]
Disaggregation Of Revenue [Line Items]
Net sales	56,354	43,892	107,632	88,374
Income before income taxes	161	(1,210)	1,571	(1,271)
Foreign [Member]
Disaggregation Of Revenue [Line Items]
Net sales	46,228	48,536	89,376	90,854
Income before income taxes	$ 750	$ 3,806	$ 1,005	$ 4,562