Cover
| Cover | Jan. 07, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 7, 2021 |
| Entity Registrant Name | Core-Mark Holding Company, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-51515 |
| Entity Tax Identification Number | 20-1489747 |
| Entity Address, Address Line One | 1500 Solana Boulevard, Suite 3400 |
| Entity Address, Postal Zip Code | 76262 |
| Entity Address, City or Town | Westlake, |
| Entity Address, State or Province | TX |
| City Area Code | 940 |
| Local Phone Number | 293-8600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | CORE |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001318084 |