v3.19.3
Document and Entity Information
Oct. 24, 2019
Cover [Abstract]  
Entity Registrant Name CASS INFORMATION SYSTEMS INC
Amendment Flag false
Entity Central Index Key 0000708781
Document Type 8-K
Document Period End Date Oct. 24, 2019
Entity Incorporation State Country Code MO
Entity File Number 000-20827
Entity Tax Identification Number 43-1265338
Entity Address, Address Line One 12444 Powerscourt Drive
Entity Address, Address Line Two Suite 550
Entity Address, City or Town St. Louis
Entity Address, State or Province MO
Entity Address, Postal Zip Code 63131
City Area Code (314)
Local Phone Number 506-5500
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common stock, par value $.50
Trading Symbol CASS
Security Exchange Name NASDAQ
Entity Emerging Growth Company false