XML 39 R28.htm IDEA: XBRL DOCUMENT
v3.21.2

Securities (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2021
Securities |
Schedule of amortized cost, unrealized gains and losses and fair values of securities classified available for sale and held to maturity | The table below provides the amortized cost, unrealized gains and losses, and fair values of debt securities summarized by major category (dollars in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | As of June 30, 2021
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | ​ | ​ | ​ | Fair
​ |  | Cost |  | Gains |  | Losses |  | ​ | ACL |  | Value
Debt securities available for sale | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
U.S. Treasury securities | ​ | $ | 212,022 | ​ | $ | 150 | ​ | $ | (279) | ​ | $ | — | ​ | $ | 211,893
Obligations of U.S. government corporations and agencies | ​ |  | 49,528 | ​ |  | 1,470 | ​ |  | — | ​ | ​ | — | ​ |  | 50,998
Obligations of states and political subdivisions | ​ |  | 292,221 | ​ |  | 9,634 | ​ |  | (513) | ​ | ​ | — | ​ |  | 301,342
Commercial mortgage-backed securities | ​ | ​ | 513,067 | ​ | ​ | 6,528 | ​ | ​ | (5,543) | ​ | ​ | — | ​ | ​ | 514,052
Residential mortgage-backed securities | ​ |  | 1,837,271 | ​ |  | 16,875 | ​ |  | (11,952) | ​ | ​ | — | ​ |  | 1,842,194
Asset-backed securities | ​ | ​ | 246,998 | ​ | ​ | 179 | ​ | ​ | (180) | ​ | ​ | — | ​ | ​ | 246,997
Corporate debt securities | ​ |  | 296,397 | ​ |  | 1,457 | ​ |  | (813) | ​ | ​ | — | ​ |  | 297,041
Total debt securities available for sale | ​ | $ | 3,447,504 | ​ | $ | 36,293 | ​ | $ | (19,280) | ​ | $ | — | ​ | $ | 3,464,517
​ ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | As of December 31, 2020
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | Unrealized | ​ | Unrealized | ​ | ​ | ​ | ​ | Fair
​ |  | Cost |  | Gains |  | Losses |  | ​ | ACL |  | Value
Debt securities available for sale | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
U.S. Treasury securities | ​ | $ | 27,481 | ​ | $ | 356 | ​ | $ | — | ​ | $ | — | ​ | $ | 27,837
Obligations of U.S. government corporations and agencies | ​ |  | 67,406 | ​ |  | 2,162 | ​ |  | (49) | ​ | ​ | — | ​ |  | 69,519
Obligations of states and political subdivisions | ​ |  | 292,940 | ​ |  | 11,779 | ​ |  | (8) | ​ | ​ | — | ​ |  | 304,711
Commercial mortgage-backed securities | ​ | ​ | 408,716 | ​ | ​ | 10,212 | ​ | ​ | (312) | ​ | ​ | — | ​ | ​ | 418,616
Residential mortgage-backed securities | ​ |  | 1,344,047 | ​ |  | 24,571 | ​ |  | (303) | ​ | ​ | — | ​ |  | 1,368,315
Corporate debt securities | ​ |  | 70,953 | ​ |  | 1,237 | ​ |  | (1) | ​ | ​ | — | ​ |  | 72,189
Total debt securities available for sale | ​ | $ | 2,211,543 | ​ | $ | 50,317 | ​ | $ | (673) | ​ | ​ | — | ​ | $ | 2,261,187
Schedule of amortized cost and fair value of debt securities available for sale and held to maturity by contractual maturity | All mortgage-backed securities were issued by U.S. government corporations and agencies (dollars in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | As of June 30, 2021
​ |  | Amortized |  | Fair
​ |  | Cost |  | Value
Debt securities available for sale | ​ | ​ | ​ | ​ | ​ | ​
Due in one year or less | ​ | $ | 122,809 | ​ | $ | 123,502
Due after one year through five years | ​ |  | 573,422 | ​ |  | 579,219
Due after five years through ten years | ​ |  | 398,111 | ​ |  | 407,150
Due after ten years | ​ |  | 2,353,162 | ​ |  | 2,354,646
Total debt securities available for sale | ​ | $ | 3,447,504 | ​ | $ | 3,464,517
Schedule of realized gains and losses related to sales of securities | Realized gains and losses related to sales and calls of debt securities available for sale are summarized as follows (dollars in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended June 30, | ​ | Six Months Ended June 30,
​ |  | 2021 |  | 2020 |  | 2021 |  | 2020
Realized gains and losses on sales of debt securities | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Gross security gains | ​ | $ | 499 | ​ | $ | 146 | ​ | $ | 524 | ​ | $ | 1,707
Gross security (losses) | ​ | ​ | (405) | ​ | ​ | (3) | ​ | ​ | (405) | ​ | ​ | (8)
Net gains (losses) on sales of debt securities (1) | ​ | $ | 94 | ​ | $ | 143 | ​ | $ | 119 | ​ | $ | 1,699
| (1) | Net gains (losses) on sales of securities reported on the unaudited Consolidated Statements of Income includes sales of equity securities, excluded in this table.
Schedule of securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position | The following information pertains to debt securities with gross unrealized losses, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (dollars in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | As of June 30, 2021
​ | ​ | Less than 12 months | ​ | 12 months or more | ​ | Total
​ | ​ | Fair |  | Unrealized |  | Fair |  | Unrealized |  | Fair |  | Unrealized
​ |  | Value |  | Losses |  | Value |  | Losses |  | Value |  | Losses
Debt securities available for sale | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
U.S. Treasury securities | ​ | $ | 150,811 | ​ | $ | (279) | ​ | $ | — | ​ | $ | — | ​ | $ | 150,811 | ​ | $ | (279)
Obligations of states and political subdivisions | ​ | ​ | 48,579 | ​ | ​ | (513) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 48,579 | ​ | ​ | (513)
Commercial mortgage-backed securities | ​ | ​ | 322,082 | ​ | ​ | (5,543) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 322,082 | ​ | ​ | (5,543)
Residential mortgage-backed securities | ​ |  | 1,073,263 | ​ |  | (11,948) | ​ |  | 344 | ​ |  | (4) | ​ |  | 1,073,607 | ​ |  | (11,952)
Asset-backed securities | ​ | ​ | 98,703 | ​ | ​ | (180) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 98,703 | ​ | ​ | (180)
Corporate debt securities | ​ |  | 200,076 | ​ |  | (813) | ​ |  | — | ​ |  | — | ​ |  | 200,076 | ​ |  | (813)
Total temporarily impaired securities | ​ | $ | 1,893,514 | ​ | $ | (19,276) | ​ | $ | 344 | ​ | $ | (4) | ​ | $ | 1,893,858 | ​ | $ | (19,280)
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | As of December 31, 2020
​ | ​ | Less than 12 months | ​ | 12 months or more | ​ | Total
​ | ​ | Fair |  | Unrealized |  | Fair |  | Unrealized |  | Fair |  | Unrealized
​ |  | Value |  | Losses |  | Value |  | Losses |  | Value |  | Losses
Debt securities available for sale | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Obligations of U.S. government corporations and agencies | ​ | $ | — | ​ | $ | — | ​ | $ | 4,957 | ​ | $ | (49) | ​ | $ | 4,957 | ​ | $ | (49)
Obligations of states and political subdivisions | ​ | ​ | 762 | ​ | ​ | (8) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 762 | ​ | ​ | (8)
Commercial mortgage-backed securities | ​ | ​ | 129,655 | ​ | ​ | (312) | ​ | ​ | — | ​ | ​ | — | ​ | ​ | 129,655 | ​ | ​ | (312)
Residential mortgage-backed securities | ​ |  | 89,997 | ​ |  | (300) | ​ |  | 139 | ​ |  | (3) | ​ |  | 90,136 | ​ |  | (303)
Corporate debt securities | ​ |  | 1,499 | ​ |  | (1) | ​ |  | — | ​ |  | — | ​ |  | 1,499 | ​ |  | (1)
Total temporarily impaired securities | ​ | $ | 221,913 | ​ | $ | (621) | ​ | $ | 5,096 | ​ | $ | (52) | ​ | $ | 227,009 | ​ | $ | (673)

X
- Definition Tabular disclosure of the reconciliation of available-for-sale and held to maturity securities from cost basis to fair value. + References No definition available. + Details
Name: | buse_ScheduleOfAvailableForSaleAndHeldToMaturitySecuritiesReconciliationTableTextBlock
Namespace Prefix: | buse_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of fair value 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. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563 + Details
Name: | us-gaap_ScheduleOfRealizedGainLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration