SEC Filing Details Document Details Form 8-K Filing Date Jun 17, 2020 Document Date Jun 17, 2020 Form Description Report of unscheduled material events or corporate event Filing Group Current Reports Company Koppers Holdings, Inc. Issuer Koppers Holdings Inc. Filing Formats View HTML Download PDF Download DOC Download XLS XBRL XBRL Viewer EX-101.SCH - XBRL TAXONOMY EXTENSION SCHEMA EX-101.LAB - XBRL TAXONOMY EXTENSION LABEL LINKBASE EX-101.PRE - XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE XML - XBRL INSTANCE DOCUMENT