Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense on intangible assets	$ 1,838	$ 2,340	$ 5,514	$ 7,022

The process of expensing the cost of an intangible asset over the estimated useful life of the asset.

No definition available.

Name:	ubsi_AmortizationExpenseOnIntangibleAssets
Namespace Prefix:	ubsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration