v3.25.2
Cover page - shares
6 Months Ended
Jun. 30, 2025
Jul. 25, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 000-51280  
Entity Registrant Name MORNINGSTAR, INC.  
Entity Central Index Key 0001289419  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Title of 12(b) Security Common stock, no par value  
Entity Incorporation, State or Country Code IL  
Entity Tax Identification Number 36-3297908  
Entity Address, Address Line One 22 West Washington Street  
Entity Address, City or Town Chicago,  
Entity Address, State or Province IL  
Entity Address, Postal Zip Code 60602  
Trading Symbol MORN  
Security Exchange Name NASDAQ  
City Area Code 312  
Local Phone Number 696-6000  
Entity Current Reporting Status Yes  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Interactive Data Current Yes  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   42,177,737