Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Year Focus	2020
Document Period End Date	Mar. 31, 2020
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Registrant Name	UNITED BANKSHARES INC/WV
Entity Central Index Key	0000729986
Entity Current Reporting Status	Yes
Trading Symbol	UBSI
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		101,723,600
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Entity File Number	002-86947
Security Exchange Name	NASDAQ
Entity Tax Identification Number	55-0641179
Entity Address, Address Line One	300 United Center
Entity Address, Address Line Two	500 Virginia Street, East
Entity Address, City or Town	Charleston
Entity Address, State or Province	WV
Entity Address, Postal Zip Code	25301
City Area Code	304
Local Phone Number	424-8716
Entity Incorporation, State or Country Code	WV