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

Represents the maximum monthly outstanding amount of securities which an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price that is also known as a repurchase agreement, or repo.

No definition available.

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

Represents the weighted average interest rate at the end of the period of securities which an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price that is also known as a repurchase agreement, or repo.

No definition available.

Name:	buse_SecuritiesSoldUnderAgreementsToRepurchaseWeightedAverageInterestRateAtPeriodEnd
Namespace Prefix:	buse_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the weighted average interest rate during the period of securities which an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price that is also known as a repurchase agreement, or repo.

No definition available.

Name:	buse_SecuritiesSoldUnderAgreementsToRepurchaseWeightedAverageInterestRateDuringPeriod
Namespace Prefix:	buse_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the maximum maturity period of securities sold under agreements to repurchase, which are classified as secured borrowings.

No definition available.

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

- Details

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

Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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 210.9-03.13(1))

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

-Publisher FASB

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

-Publisher SEC

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

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-Name Accounting Standards Codification

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

-Publisher FASB

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-Topic 235

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