Discontinued Operations - Summary of Cash Flows from Discontinued Operations Included in Condensed Consolidated Statements of Cash Flows (Detail) - Specialty Papers [Member] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net cash used by operating activities	$ (238)	$ (945)
Change in cash and cash equivalents from discontinued operations	$ (238)	$ (945)