Business Segment Information - Net Sales and Income from Operation by Business Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 71,892	$ 80,486
Income from operations	3,054	4,239
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Income from operations	(6,938)	(7,414)
Engineered Systems [Member]
Segment Reporting Information [Line Items]
Net sales	42,057	50,646
Income from operations	6,170	8,557
Industrial Process Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	29,835	29,840
Income from operations	$ 3,822	$ 3,096