The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting Information
Amortization expense	$ 8.9	$ 7.4	$ 26.8	$ 21.4
Trademarks
Segment Reporting Information
Impairment losses	16.1		18.2
Sealing Products
Segment Reporting Information
Accumulated impairment losses	27.8		27.8		$ 27.8
Engineered Products
Segment Reporting Information
Accumulated impairment losses	$ 154.8		$ 154.8		$ 154.8