Provision (Reduction In Reserve) For Loan Losses

No definition available.

Name:	usbi_ProvisionReductionInReserveForLoanLosses
Namespace Prefix:	usbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossAdditionalInformationAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(4)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Loans and Allowance for Loan Losses - Schedule of Changes in Allowance for Loan Losses and Recorded Investment in Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended					9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Other Loans [Member]	Dec. 31, 2013 Other Loans [Member]	Sep. 30, 2014 FUSB & ALC [Member]	Dec. 31, 2013 FUSB & ALC [Member]	Sep. 30, 2014 FUSB & ALC [Member] Commercial [Member]	Dec. 31, 2013 FUSB & ALC [Member] Commercial [Member]	Sep. 30, 2014 FUSB & ALC [Member] Commercial Real Estate [Member]	Dec. 31, 2013 FUSB & ALC [Member] Commercial Real Estate [Member]	Sep. 30, 2014 FUSB & ALC [Member] Consumer [Member]	Dec. 31, 2013 FUSB & ALC [Member] Consumer [Member]	Sep. 30, 2014 FUSB & ALC [Member] Residential Real Estate [Member]	Dec. 31, 2013 FUSB & ALC [Member] Residential Real Estate [Member]	Sep. 30, 2014 FUSB & ALC [Member] Other Loans [Member]	Dec. 31, 2013 FUSB & ALC [Member] Other Loans [Member]	Sep. 30, 2014 ALC [Member]	Dec. 31, 2013 ALC [Member]	Sep. 30, 2014 ALC [Member] Consumer [Member]	Dec. 31, 2013 ALC [Member] Consumer [Member]	Sep. 30, 2014 ALC [Member] Residential Real Estate [Member]	Dec. 31, 2013 ALC [Member] Residential Real Estate [Member]	Sep. 30, 2014 FUSB [Member]	Dec. 31, 2013 FUSB [Member]	Sep. 30, 2014 FUSB [Member] Commercial [Member]	Dec. 31, 2013 FUSB [Member] Commercial [Member]	Sep. 30, 2014 FUSB [Member] Commercial Real Estate [Member]	Dec. 31, 2013 FUSB [Member] Commercial Real Estate [Member]	Sep. 30, 2014 FUSB [Member] Consumer [Member]	Dec. 31, 2013 FUSB [Member] Consumer [Member]	Sep. 30, 2014 FUSB [Member] Residential Real Estate [Member]	Dec. 31, 2013 FUSB [Member] Residential Real Estate [Member]	Sep. 30, 2014 FUSB [Member] Other Loans [Member]	Dec. 31, 2013 FUSB [Member] Other Loans [Member]
Allowance for loan losses:
Beginning balance			$ 9,396					$ 9,396	$ 19,278	$ 592	$ 977	$ 4,852	$ 14,216	$ 2,847	$ 2,901	$ 1,092	$ 1,118	$ 13	$ 66	$ 3,124	$ 3,513	$ 2,667	$ 2,733	$ 457	$ 780	$ 6,272	$ 15,765	$ 592	$ 977	$ 4,852	$ 14,216	$ 180	$ 168	$ 635	$ 338	$ 13	$ 66
Charge-offs								(3,653)	(13,131)	(281)	(537)	(899)	(8,055)	(2,201)	(3,329)	(272)	(1,210)			(2,277)	(3,504)	(2,105)	(2,979)	(172)	(525)	(1,376)	(9,627)	(281)	(537)	(899)	(8,055)	(96)	(350)	(100)	(685)
Recoveries								1,578	3,891	288	141	535	2,747	712	970	42	29	1	4	635	895	608	874	27	21	943	2,996	288	141	535	2,747	104	96	15	8	1	4
Provision for loan losses	(55)	240	95	799				95	(642)	(339)	11	(510)	(4,056)	1,019	2,305	(61)	1,155	(14)	(57)	1,145	2,220	1,067	2,039	78	181	(1,050)	(2,862)	(339)	11	(510)	(4,056)	(48)	266	(139)	974	(14)	(57)
Ending balance	7,416		7,416					7,416	9,396	260	592	3,978	4,852	2,376	2,847	802	1,092		13	2,627	3,124	2,236	2,667	391	457	4,789	6,272	260	592	3,978	4,852	140	180	411	635		13
Ending balance individually evaluated for impairment								1,329	3,069		219	1,329	2,839				11									1,329	3,069		219	1,329	2,839				11
Ending balance collectively evaluated for impairment								6,087	6,327	260	373	2,649	2,013	2,376	2,847	802	1,081		13	2,627	3,124	2,236	2,667	391	457	3,460	3,203	260	373	2,649	2,013	140	180	411	624		13
Loan receivables:
Ending balance	280,226		280,226		315,433	403	604	280,226	315,433	18,216	37,772	142,845	156,634	65,227	58,824	53,535	61,599	403	604	80,176	75,559	57,508	48,938	22,668	26,621	200,050	239,874	18,216	37,772	142,845	156,634	7,719	9,886	30,867	34,978	403	604
Ending balance individually evaluated for impairment								11,148	32,551		753	11,148	28,813				2,985									11,148	32,551		753	11,148	28,813				2,985
Ending balance collectively evaluated for impairment								$ 269,078	$ 282,882	$ 18,216	$ 37,019	$ 131,697	$ 127,821	$ 65,227	$ 58,824	$ 53,535	$ 58,614	$ 403	$ 604	$ 80,176	$ 75,559	$ 57,508	$ 48,938	$ 20,668	$ 26,621	$ 188,902	$ 207,323	$ 18,216	$ 37,019	$ 131,697	$ 127,821	$ 7,719	$ 9,886	$ 30,867	$ 31,993	$ 403	$ 604