Credit Quality - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2021 Contract	Jun. 30, 2022 USD ($) Contract	Jun. 30, 2021 Contract	Dec. 31, 2021 USD ($)
Minimum days for discontinue of accrual interest on commercial and consumer loan		90 days
Maximum days for discontinue of accrual interest on commercial and consumer loan		120 days
Troubled debt restructuring		$ 25,504		$ 35,856
Restructured loans on nonaccrual status		$ 11,298		22,421
Minimum number of days required for special mention		30 days
Maximum number of days required for special mention		89 days
Number of days required for substandard		90 days
OREO		$ 13,847		14,823
Recorded investment of consumer mortgage loans				13
Troubled debt restructurings post modification additional funds recorded investment		49
Payments under funding commitments		$ 65
Description of Credit Risk Exposure		For United’s loans with a corporate credit exposure, United analyzes loans individually to classify the loans as to credit risk. Review and analysis of criticized (special mention-rated loans in the amount of $1,000 or greater) and classified (substandard-rated and worse in the amount of $500 and greater) loans is completed once per quarter. Review of notes with committed exposure of $2,000 or greater is completed at least annually.
No of eligible loan modifications received | Contract	2	1	3
Loans Modification Explanation		This program ended on January 1, 2022. As provided for under the CARES Act, these loan modifications are exempt by law from classification as a TDR as defined by GAAP.
Mortgage Loan Related to Property Sales		$ 0
Temporary Relief from Troubled Debt Restructurings [Member] | Covid 19 [Member]
No of eligible loan modifications received		40
Restructured loans modified by temporary relief from trouble debt restructurings amount during period		$ 2,031
No of eligible loan modifications outstanding		188
Troubled debt restructuring		$ 18,039
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Minimum days for discontinue of accrual interest on commercial and consumer loan		90 days
Restructured loans on nonaccrual status		$ 3,162		$ 102
Financing Receivables 30 To 89 Days Past Due [Member]
Restructured loans on nonaccrual status		$ 140
Financial Asset, 30 to 59 Days Past Due [Member]
Financing receivable threshold period past due				90 days