XML 106 R94.htm IDEA: XBRL DOCUMENT v3.24.1.u1

DERIVATIVE FINANCIAL INSTRUMENTS - Net Gains (Losses) Relating to Derivative Instruments (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest rate lock commitments | Mortgage revenue
Derivative [Line Items]
Net change in fair value of interest rate swaps	$ 267	$ 37
Interest rate lock commitments | Other expense
Derivative [Line Items]
Net change in fair value of interest rate swaps	5	0
Forward sales commitments | Mortgage revenue
Derivative [Line Items]
Net change in fair value of interest rate swaps	9	(54)
Forward sales commitments | Other expense
Derivative [Line Items]
Net change in fair value of interest rate swaps	$ 51	$ 0

X

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4A

+ Details

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

+ Details

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

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateLockCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=buse_GainLossOnSaleOfMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=buse_OtherNoninterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: