XML 53 R42.htm IDEA: XBRL DOCUMENT v3.19.2

Portfolio loans - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) loan	Jun. 30, 2018 USD ($) loan	Jun. 30, 2019 USD ($) loan contract	Jun. 30, 2018 USD ($) loan	Dec. 31, 2018 USD ($)
Portfolio Loans
Net deferred loan origination costs	$ 5,400		$ 5,400		$ 5,600
Amount of loan reduction due to net accretable purchase accounting adjustments	25,000		25,000		$ 13,900
Gross interest income that would have been recorded if impaired loans had been current	400	$ 300	$ 1,100	$ 700
TDRs subsequently classified as non-performing and had payment defaults		0	1	0
Minimum days past due for TDR loans to be classified as non-performing			90 days
Balance of all acquired loans	1,800,000		$ 1,800,000
Commercial
Portfolio Loans
Loans classified as a TDR	$ 600		$ 600
Performing loans classified as TDRs | loan	1		1
Commercial real estate
Portfolio Loans
Loans classified as a TDR	$ 3,200		$ 3,200
Retail real estate
Portfolio Loans
Loans classified as a TDR		$ 100		$ 100
Performing loans classified as TDRs | loan		1		1
Loans in the process of foreclosure			2,600
Maximum | Commercial real estate
Portfolio Loans
Limit where loans are processed through an expedited underwriting process			1,000
Pass and watch | Commercial
Portfolio Loans
Limit where loans are processed through an expedited underwriting process			350
Pass and watch | Minimum | Commercial
Portfolio Loans
Limit where loans are processed through an expedited underwriting process			350
Pass and watch | Maximum | Commercial
Portfolio Loans
Limit where loans are processed through an expedited underwriting process			1,000
Watch | Commercial
Portfolio Loans
Limit above which loans are annually reviewed			1,000
Special Mention
Portfolio Loans
Limit above which loans are annually reviewed			$ 350

X

- Definition

Minimum days past due for TDR loans to be classified as non-performing.

+ References

No definition available.

+ Details

Name:	buse_FinancingReceivableModificationsDefaultedMinimumPeriodPastDueToBeClassifiedAsNonPerforming
Namespace Prefix:	buse_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the limit of loan above which loans are reviewed annually.

+ References

No definition available.

+ Details

Name:	buse_LoansAndLeasesReceivableLimitAboveWhichLoansAreAnnuallyReviewed
Namespace Prefix:	buse_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Represents the limit of loan where loans are processed through an expedited underwriting process.

+ References

No definition available.

+ Details

Name:	buse_LoansAndLeasesReceivableLimitAboveWhichLoansAreProcessedThroughExpeditedUnderwritingProcess
Namespace Prefix:	buse_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of loans increased (decrease) due to net accretable purchase accounting adjustments.

+ References

No definition available.

+ Details

Name:	buse_LoansAndLeasesReceivablePeriodIncreaseDecreaseDueToNetAccretablePurchaseAccountingAdjustments
Namespace Prefix:	buse_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Represents residential real estate loans that are in the process of foreclosure.

+ References

No definition available.

+ Details

Name:	buse_LoansInProcessOfForeclosure
Namespace Prefix:	buse_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

X

- Definition

Fair value of acquired receivable from business combination, excluding certain loans and debt securities acquired in transfer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=116869197&loc=d3e4845-128472

+ Details

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

X

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

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

X

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18794-111554

+ Details

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

X

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=buse_RetailRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=buse_LoansInHighestGradesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=buse_WatchListMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: