Segment Information - Continuing Operations by Reportable Segment (Detail) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2020 segment	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment				3
Number of operating segments | segment				3
Segment Reporting Information [Line Items]
Net sales	$ 113,761		$ 120,459		$ 308,506	$ 378,838
Goodwill impairment	0		0		92,942	0
Income (loss) from operations	(1,456)		(1,811)		(116,483)	(7,457)
Interest expense	(6,873)		(3,805)		(17,036)	(8,829)
Other	118		(633)		(211)	(1,171)
Loss from continuing operations before benefit (provision) for income taxes and share of net income from joint venture	(8,211)		(6,249)		(133,730)	(17,457)
Total assets	1,316,209				1,316,209		$ 1,541,984
Power Solutions
Segment Reporting Information [Line Items]
Goodwill impairment		$ 92,900
Operating Segments | Mobile Solutions
Segment Reporting Information [Line Items]
Net sales	70,371		73,071		181,292	230,590
Goodwill impairment					0
Income (loss) from operations	4,953		3,423		625	10,118
Total assets	369,939				369,939		373,256
Operating Segments | Power Solutions
Segment Reporting Information [Line Items]
Net sales	43,415		47,430		127,307	148,480
Goodwill impairment					92,942
Income (loss) from operations	1,143		3,351		(87,737)	12,857
Total assets	199,906				199,906		310,545
Corporate and Eliminations
Segment Reporting Information [Line Items]
Net sales	(25)		(42)		(93)	(232)
Goodwill impairment					0
Income (loss) from operations	(7,552)		$ (8,585)		(29,371)	$ (30,432)
Total assets	$ 746,364				$ 746,364		$ 858,183