v3.26.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2026
May 05, 2026
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2026  
Document Transition Report false  
Entity File Number 001-32576  
Entity Registrant Name ITC HOLDINGS CORP.  
Entity Incorporation, State or Country Code MI  
Entity Tax Identification Number 32-0058047  
Entity Address, Address Line One 27175 Energy Way  
Entity Address, City or Town Novi  
Entity Address, State or Province MI  
Entity Address, Postal Zip Code 48377  
City Area Code 248  
Local Phone Number 946-3000  
Entity Current Reporting Status No  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   224,203,112
Entity Central Index Key 0001317630  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Amendment Flag false