Business Segment Information - Intra-Segment and Inter-Segment Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 74,139	$ 92,651
Energy Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	39,973	53,709
Industrial Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	17,797	23,303
Fluid Handling Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	16,207	15,816
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Net sales	162	(177)
Intra - Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(3,775)	(3,816)
Intra - Segment Sales [Member] | Energy Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	(2,469)	(2,308)
Intra - Segment Sales [Member] | Industrial Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	(791)	(890)
Intra - Segment Sales [Member] | Fluid Handling Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	(515)	(618)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	78,622	97,653
Operating Segments [Member] | Energy Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	43,128	56,039
Operating Segments [Member] | Industrial Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	18,728	24,922
Operating Segments [Member] | Fluid Handling Solutions Segment [Member]
Segment Reporting Information [Line Items]
Net sales	16,766	16,692
Inter-segment Elimination [Member] | Industrial Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(730)	(186)
Inter-segment Elimination [Member] | Energy Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(140)	(823)
Inter-segment Elimination [Member] | Corporate And Other Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	162	(177)
Inter-segment Elimination [Member] | Energy Solutions Segment [Member] | Industrial Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(686)	(22)
Inter-segment Elimination [Member] | Industrial Solutions Segment [Member] | Energy Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(140)	(729)
Inter-segment Elimination [Member] | Fluid Handling Solutions Segment [Member] | Industrial Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(44)	(164)
Inter-segment Elimination [Member] | Fluid Handling Solutions Segment [Member] | Energy Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales		(94)
Inter-segment Elimination [Member] | Corporate and Other [Member] | Corporate And Other Inter-Segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ 162	$ (177)