Segment Information about Reported Product Revenues, Depreciation and Amortization and Operating Income (Loss) (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Product revenues	$ 240,056	$ 261,504	$ 741,303	$ 792,490
Depreciation and amortization	11,064	12,898	33,281	38,721
Operating income	20,329	15,713	62,231	51,955
Industrial Segments
Segment Reporting Information [Line Items]
Product revenues	$ 11,813	$ 22,655	41,003	68,070
Industrial Segments \| CSZ-IC
Segment Reporting Information [Line Items]
Product revenues			3,418	30,460
Depreciation and amortization			0	1,894
Operating income			$ 206	$ 659

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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