Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 30, 2020
Entity Information [Line Items]
Document Type	10-Q
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 Central Index Key	0001317630
Current Fiscal Year End Date	--12-31
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Common Stock, Shares Outstanding	true
Amendment Flag	false
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