v3.25.4
DOCUMENT AND ENTITY INFORMATION - USD ($)
 12 Months Ended
Dec. 31, 2025
Feb. 23, 2026
Jun. 30, 2025
Entity Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Document Transition Report false    
Entity File Number 001-34034    
Entity Registrant Name REGIONS FINANCIAL CORPORATION    
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Central Index Key 0001281761    
Current Fiscal Year End Date --12-31    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 63-0589368    
Entity Address, Address Line One 1900 Fifth Avenue North    
Entity Address, City or Town Birmingham    
Entity Address, State or Province AL    
Entity Address, Postal Zip Code 35203    
City Area Code 800    
Local Phone Number 734-4667    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 20,566,150,882
Entity Common Stock, Shares Outstanding   863,506,691  
Documents Incorporated by Reference
Portions of the definitive proxy statement for the registrant's 2026 Annual Meeting of Shareholders to be filed within 120 days of the registrant's fiscal year end are incorporated by reference into Part III of this report to the extent described therein.
    
Common Stock      
Entity Information [Line Items]      
Title of 12(b) Security Common Stock, $.01 par value    
Trading Symbol RF    
Security Exchange Name NYSE    
Series C      
Entity Information [Line Items]      
Title of 12(b) Security 5.700% Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series C    
Trading Symbol RF PRC    
Security Exchange Name NYSE    
Series E      
Entity Information [Line Items]      
Title of 12(b) Security 4.45% Non-Cumulative Perpetual Preferred Stock, Series E    
Trading Symbol RF PRE    
Security Exchange Name NYSE    
Series F Preferred Stock      
Entity Information [Line Items]      
Title of 12(b) Security Non-Cumulative Perpetual Preferred Stock, Series F    
Trading Symbol RF PRF    
Security Exchange Name NYSE