0001227654 2021-03-31 2021-03-31 0001227654 false 8-K 2021-03-31 Compass Minerals International, Inc. DE 001-31921 36-3972986 9900 West 109th Street Suite 100 Overland Park KS 66210 913 344-9200 false false false false Common stock, $0.01 par value CMP NYSE false 2021-03-31 2021-03-31