XML 67 R55.htm IDEA: XBRL DOCUMENT
v3.21.1

Borrowings - Senior notes and Subordinate Notes (Details) - USD ($) $ in Thousands | Jun. 01, 2020 | May 25, 2017 | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | ---
Long-term debt |  |  |  |
Unamortized debt issuance cost |  |  | $ 2,787 | $ 2,965
3.75% notes maturing May 25, 2022 | Senior notes |  |  |  |
Long-term debt |  |  |  |
Issuance of debt |  | $ 40,000 |  |
Interest rate (as a percent) |  | 3.75% |  |
Unamortized debt issuance cost |  |  | 157 | 191
4.75% notes maturing May 25, 2027 | Subordinated debt |  |  |  |
Long-term debt |  |  |  |
Issuance of debt |  | $ 60,000 |  |
Fixed payment term of note |  | 5 years |  |
Duration of fixed interest rate |  | 5 years |  |
Unamortized debt issuance cost |  |  | 625 | 651
4.75% notes maturing May 25, 2027 | First Five Years | Subordinated debt |  |  |  |
Long-term debt |  |  |  |
Interest rate (as a percent) |  | 4.75% |  |
4.75% notes maturing May 25, 2027 | Three-month LIBOR | Subordinated debt |  |  |  |
Long-term debt |  |  |  |
Floating interest rate margin (as a percent) |  | 2.919% |  |
5.25% notes maturing June 1, 2030 | Subordinated debt |  |  |  |
Long-term debt |  |  |  |
Issuance of debt | $ 125,000 |  |  |
Duration of fixed interest rate | 5 years |  |  |
Floating interest rate margin (as a percent) | 5.11% |  |  |
Unamortized debt issuance cost |  |  | $ 2,005 | $ 2,123
5.25% notes maturing June 1, 2030 | First Five Years | Subordinated debt |  |  |  |
Long-term debt |  |  |  |
Interest rate (as a percent) | 5.25% |  |  |

X
- Definition Fixed payment term of note. + References No definition available. + Details
Name: | buse_DebtInstrumentFixedPaymentTerm
Namespace Prefix: | buse_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Term for which interest rate of debt is fixed. + References No definition available. + Details
Name: | buse_DurationOfFixedInterestRate
Namespace Prefix: | buse_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + 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 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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=120391452&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=119993939&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=buse_May252022MaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=buse_May252027MaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SubordinatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=buse_June12030MaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |