XML 15 R1.htm IDEA: XBRL DOCUMENT

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-31940
Entity Registrant Name	FNB CORP/PA/
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	25-1255406
Entity Address, Address Line One	One North Shore Center,
Entity Address, Address Line Two	12 Federal Street,
Entity Address, City or Town	Pittsburgh,
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15212
City Area Code	800
Local Phone Number	555-5455
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
Entity Shell Company	false
Entity Public Float			$ 2,364,996,210
Entity Common Stock, Shares Outstanding		321,523,121
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of F.N.B. Corporation’s definitive proxy statement to be filed pursuant to Regulation 14A for the Annual Meeting of Stockholders to be held on May 11, 2021 are incorporated by reference into Part III, Items 10, 11, 12, 13 and 14, of this Annual Report on Form 10-K. F.N.B. Corporation will file its definitive proxy statement with the Securities and Exchange Commission on or before April 15, 2021.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000037808
NEW YORK STOCK EXCHANGE, INC. \| Common Stock, par value $0.01 per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	FNB
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. \| Depositary Shares each representing 1/40th interest in a share of Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series E
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares each representing 1/40th interest in a share of Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series E
Trading Symbol	FNBPrE
Security Exchange Name	NYSE