v3.26.1
BUSINESS SEGMENTS - Schedule of Financial Information for Segments of FNB (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Segment Reporting Information [Line Items]      
Interest income $ 569.0 $ 559.0  
Interest expense 210.0 236.0  
Net Interest Income 359.0 323.0  
Provision for Credit Losses 18.5 17.5  
Non-interest income:      
Service charges 23.0 22.0  
Interchange and card transaction fees 13.0 12.0  
Trust services 13.0 13.0  
Insurance commissions and fees 6.0 6.0  
Securities commissions and fees 9.0 9.0  
Capital markets income 7.0 5.0  
Mortgage banking operations 6.0 7.0  
Other 14.0 14.0  
Total Non-Interest Income 91.0 88.0  
Non-interest expense:      
Salaries and employee benefits 136.0 135.0  
Other 122.0 111.0  
Total Non-Interest Expense 258.0 246.0  
Income tax expense (benefit) 37.0 31.0  
Net Income 137.0 117.0  
Total assets 50,628.0 49,020.0 $ 50,229.0
Total Loans and Leases 35,112.0 [1] 34,235.0 34,777.0 [1]
Total deposits 38,901.0 37,239.0 $ 38,759.0
Market value of assets under administration - FNBIA, FNTC and FNIS 15,102.0 13,897.0  
Operating Segments | Community Banking      
Segment Reporting Information [Line Items]      
Interest income 567.0 558.0  
Interest expense 202.0 221.0  
Net Interest Income 365.0 337.0  
Provision for Credit Losses 18.0 17.0  
Non-interest income:      
Service charges 23.0 22.0  
Interchange and card transaction fees 13.0 12.0  
Trust services 0.0 0.0  
Insurance commissions and fees 0.0 0.0  
Securities commissions and fees 0.0 0.0  
Capital markets income 5.0 4.0  
Mortgage banking operations 6.0 7.0  
Other 17.0 18.0  
Total Non-Interest Income 64.0 63.0  
Non-interest expense:      
Salaries and employee benefits 120.0 121.0  
Other 112.0 101.0  
Total Non-Interest Expense 232.0 222.0  
Income tax expense (benefit) 39.0 34.0  
Net Income 140.0 127.0  
Total assets 50,287.0 48,668.0  
Total Loans and Leases 35,062.0 34,191.0  
Total deposits 39,227.0 38,087.0  
Market value of assets under administration - FNBIA, FNTC and FNIS 0.0 0.0  
Operating Segments | Wealth Management      
Segment Reporting Information [Line Items]      
Interest income 0.0 0.0  
Interest expense 0.0 0.0  
Net Interest Income 0.0 0.0  
Provision for Credit Losses 0.0 0.0  
Non-interest income:      
Service charges 0.0 0.0  
Interchange and card transaction fees 0.0 0.0  
Trust services 13.0 13.0  
Insurance commissions and fees 0.0 0.0  
Securities commissions and fees 9.0 9.0  
Capital markets income 0.0 0.0  
Mortgage banking operations 0.0 0.0  
Other 0.0 0.0  
Total Non-Interest Income 22.0 22.0  
Non-interest expense:      
Salaries and employee benefits 11.0 10.0  
Other 3.0 4.0  
Total Non-Interest Expense 14.0 14.0  
Income tax expense (benefit) 2.0 2.0  
Net Income 6.0 6.0  
Total assets 50.0 50.0  
Total Loans and Leases 0.0 0.0  
Total deposits 0.0 0.0  
Market value of assets under administration - FNBIA, FNTC and FNIS 15,102.0 13,897.0  
Operating Segments | Insurance      
Segment Reporting Information [Line Items]      
Interest income 0.0 0.0  
Interest expense 0.0 0.0  
Net Interest Income 0.0 0.0  
Provision for Credit Losses 0.0 0.0  
Non-interest income:      
Service charges 0.0 0.0  
Interchange and card transaction fees 0.0 0.0  
Trust services 0.0 0.0  
Insurance commissions and fees 6.0 6.0  
Securities commissions and fees 0.0 0.0  
Capital markets income 0.0 0.0  
Mortgage banking operations 0.0 0.0  
Other 0.0 0.0  
Total Non-Interest Income 6.0 6.0  
Non-interest expense:      
Salaries and employee benefits 4.0 4.0  
Other 1.0 1.0  
Total Non-Interest Expense 5.0 5.0  
Income tax expense (benefit) 0.0 0.0  
Net Income 1.0 1.0  
Total assets 33.0 35.0  
Total Loans and Leases 0.0 0.0  
Total deposits 0.0 0.0  
Market value of assets under administration - FNBIA, FNTC and FNIS 0.0 0.0  
Parent and Other      
Segment Reporting Information [Line Items]      
Interest income 2.0 1.0  
Interest expense 8.0 15.0  
Net Interest Income (6.0) (14.0)  
Provision for Credit Losses 0.0 0.0  
Non-interest income:      
Service charges 0.0 0.0  
Interchange and card transaction fees 0.0 0.0  
Trust services 0.0 0.0  
Insurance commissions and fees 0.0 0.0  
Securities commissions and fees 0.0 0.0  
Capital markets income 2.0 1.0  
Mortgage banking operations 0.0 0.0  
Other (3.0) (4.0)  
Total Non-Interest Income (1.0) (3.0)  
Non-interest expense:      
Salaries and employee benefits 1.0 0.0  
Other 6.0 5.0  
Total Non-Interest Expense 7.0 5.0  
Income tax expense (benefit) (4.0) (5.0)  
Net Income (10.0) (17.0)  
Total assets 258.0 267.0  
Total Loans and Leases 50.0 44.0  
Total deposits (326.0) (848.0)  
Market value of assets under administration - FNBIA, FNTC and FNIS $ 0.0 $ 0.0  
[1] Amount represents loans for which we have elected the fair value option. See Note 19.