v3.19.2
Cover - shares
6 Months Ended
Jun. 30, 2019
Aug. 02, 2019
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2019  
Document Transition Report false  
Entity File Number 000-51515  
Entity Registrant Name Core-Mark Holding Company, Inc.  
Entity Incorporation, State or Country Code DE  
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  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Trading Symbol CORE  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   45,879,515
Entity Central Index Key 0001318084  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Amendment Flag false