Revenue - Net Sales (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Net sales	$ 397,904	$ 419,432
Forged and Cast Mill Rolls [Member]
Disaggregation Of Revenue [Line Items]
Net sales	286,036	270,241
Forged Engineered Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	19,594	59,289
Heat Exchange Coils [Member]
Disaggregation Of Revenue [Line Items]
Net sales	27,973	26,761
Centrifugal Pumps [Member]
Disaggregation Of Revenue [Line Items]
Net sales	36,001	35,868
Air Handling Systems [Member]
Disaggregation Of Revenue [Line Items]
Net sales	28,300	27,273
U.S. [Member]
Disaggregation Of Revenue [Line Items]
Net sales	192,845	209,536
Foreign [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 205,059	$ 209,896