v3.26.1
Document and Entity Information
May 07, 2026
Cover [Abstract]  
Entity Registrant Name CSG SYSTEMS INTERNATIONAL INC
Amendment Flag false
Entity Central Index Key 0001005757
Document Type 8-K
Document Period End Date May 07, 2026
Entity Incorporation State Country Code DE
Entity File Number 0-27512
Entity Tax Identification Number 47-0783182
Entity Address, Address Line One 169 Inverness Dr W
Entity Address, Address Line Two Ste 300
Entity Address, City or Town Englewood
Entity Address, State or Province CO
Entity Address, Postal Zip Code 80112
City Area Code (303)
Local Phone Number 200-2000
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, par value $0.01 per share
Trading Symbol CSGS
Security Exchange Name NASDAQ
Entity Emerging Growth Company false