XML 54 R44.htm IDEA: XBRL DOCUMENT
v3.23.1

Debt Securities - Additional Information (Details) $ in Thousands | Mar. 31, 2023 USD ($) security | Dec. 31, 2022 USD ($) security
--- | --- | ---
Available for Sale |  |
Debt securities with gross unrealized or unrecognized losses, fair value | $ | $ 2,339,952 | $ 2,439,533
Gross unrealized or unrecognized losses on debt securities | $ | $ 280,583 | $ 311,204
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses | 12.00% | 12.80%
Count of debt securities | security | 1,058 | 1,091
Count of debt securities in an unrealized or unrecognized loss position | security | 947 | 1,032
Held to Maturity |  |
Debt securities with gross unrealized or unrecognized losses, fair value | $ | $ 780,653 | $ 785,295
Gross unrealized or unrecognized losses on debt securities | $ | $ 126,906 | $ 133,017
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses | 16.30% | 16.90%
Count of debt securities | security | 55 | 55
Count of debt securities in an unrealized or unrecognized loss position | security | 55 | 55
Total |  |
Debt securities with gross unrealized or unrecognized losses, fair value | $ | $ 3,120,605 | $ 3,224,828
Gross unrealized or unrecognized losses on debt securities | $ | $ 407,489 | $ 444,221
Ratio of gross unrealized or unrecognized losses to debt securities with gross unrealized or unrecognized losses | 13.10% | 13.80%
Count of debt securities | security | 1,113 | 1,146
Count of debt securities in an unrealized or unrecognized loss position | security | 1,002 | 1,087

X
- Definition N/A + References No definition available. + Details
Name: | buse_AvailableForSaleAndHeldToMaturityDebtSecuritiesInUnrealizedLossPositionAbstract
Namespace Prefix: | buse_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition N/A + References No definition available. + Details
Name: | buse_AvailableForSaleDebtSecuritiesInUnrealizedLossPositionAbstract
Namespace Prefix: | buse_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the total number of securities in the investment portfolio which are in an unrealized loss position as a percentage of the aggregate carrying value. + References No definition available. + Details
Name: | buse_AvailableForSaleSecuritiesInUnrealizedLossPositionsAsPercentageOfAggregateCarryingValue
Namespace Prefix: | buse_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gross total of unrealized losses on debt securities. + References No definition available. + Details
Name: | buse_DebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | buse_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of total debt securities. + References No definition available. + Details
Name: | buse_DebtSecuritiesFairValue
Namespace Prefix: | buse_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (held to maturity), in unrealized loss position. + References No definition available. + Details
Name: | buse_DebtSecuritiesHeldToMaturityUnrealizedLossPositionNumberOfPositions
Namespace Prefix: | buse_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total count of debt securities in an unrealized loss position. + References No definition available. + Details
Name: | buse_DebtSecuritiesUnrealizedLossPositionNumberOfPositions
Namespace Prefix: | buse_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the total number of securities in the investment portfolio which are in an unrealized loss position as a percentage of the aggregate carrying value. + References No definition available. + Details
Name: | buse_HeldForMaturitySecuritiesInUnrealizedLossPositionsAsPercentageOfAggregateCarryingValue
Namespace Prefix: | buse_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition N/A + References No definition available. + Details
Name: | buse_HeldToMaturityDebtSecuritiesInUnrealizedLossPositionAbstract
Namespace Prefix: | buse_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the total number of securities in the investment portfolio which are in an unrealized loss position as a percentage of the aggregate carrying value. + References No definition available. + Details
Name: | buse_SecuritiesInUnrealizedLossPositionsAsPercentageOfAggregateCarryingValue
Namespace Prefix: | buse_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total count of debt securities. + References No definition available. + Details
Name: | buse_TotalCountOfDebtSecurities
Namespace Prefix: | buse_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total count of available for sale debt securities. + References No definition available. + Details
Name: | buse_TotalCountOfDebtSecuritiesAvailableForSaleSecurities
Namespace Prefix: | buse_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total count of held to maturity debt securities. + References No definition available. + Details
Name: | buse_TotalCountOfDebtSecuritiesHeldToMaturity
Namespace Prefix: | buse_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant