SEC Filing Details Document Details Form 10-Q Filing Date May 7, 2021 Document Date Mar 31, 2021 Form Description Quarterly report which provides a continuing view of a company's financial position Filing Group Quarterly Filings Company Koppers Holdings, Inc. Issuer Koppers Holdings Inc. Filing Formats iXBRL View HTML Download PDF Download DOC Download XLS XBRL XBRL Viewer EX-101.SCH - XBRL TAXONOMY EXTENSION SCHEMA EX-101.CAL - XBRL TAXONOMY EXTENSION CALCULATION LINKBASE EX-101.DEF - XBRL TAXONOMY EXTENSION DEFINITION LINKBASE EX-101.LAB - XBRL TAXONOMY EXTENSION LABEL LINKBASE EX-101.PRE - XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE XML - XBRL INSTANCE DOCUMENT