Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 322	$ 327	$ 643	$ 659
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Estimated intangible asset amortization expense remainder of fiscal year	1,300		1,300
Estimated intangible asset amortization expense 2020	1,200		1,200
Estimated intangible asset amortization expense 2021	1,200		1,200
Estimated intangible asset amortization expense 2022	1,200		1,200
Estimated intangible asset amortization expense 2023	1,200		1,200
Goodwill [Line Items]
Goodwill	7,624		7,624		$ 7,576	$ 8,045
Global Seating
Goodwill [Line Items]
Goodwill	5,200		5,200
Electrical Systems
Goodwill [Line Items]
Goodwill	$ 2,400		$ 2,400