Divestitures - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 30, 2018	Feb. 28, 2018	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Oct. 24, 2018
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Estimated gain (loss) on disposal			$ (15,074)		$ (3,970)
Strobic Air Corporation [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale price, subject to post-closing purchase price adjustments	$ 28,500
Estimated gain (loss) on disposal				$ 6,900
Net proceeds after adjustments	27,900
Net assets disposed	18,800
Transaction-related cost	2,200
Goodwill	13,000
Net sales						$ 17,700
Income from operations						$ 1,600
Strobic Air Corporation [Member] | Definite-Lived Intangible Assets [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Intangible assets	2,300
Strobic Air Corporation [Member] | Indefinite-Lived Intangible Assets [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Intangible assets	$ 1,200
Keystone Filter [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Sale price, subject to post-closing purchase price adjustments		$ 7,500
Estimated gain (loss) on disposal				$ 4,300
Net proceeds after adjustments		7,200
Net assets disposed		2,700
Transaction-related cost		$ 200
Zhongli [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Estimated gain (loss) on disposal			(15,100)
Net assets disposed			$ 24,497		$ 24,497
Disposal group, Consideration receivable							$ 3,600
Expected closing period of sales agreement					90 days