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v3.22.2.2

Borrowings - Additional information (Details) |  | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Feb. 24, 2020 USD ($) | Sep. 30, 2022 USD ($) item | Jun. 30, 2022 USD ($) | Dec. 31, 2016 | Sep. 30, 2022 USD ($) item | Dec. 31, 2021 USD ($) | Jun. 30, 2021 USD ($) | Apr. 20, 2018 USD ($)
Borrowings |  |  |  |  |  |  |  |
Securities available-for-sale, at fair value |  | $ 1,609,759,000 |  |  | $ 1,609,759,000 | $ 1,693,632,000 |  |
Number of customers having secured balances exceeding specified percentage of stockholders equity | item |  | 0 |  |  | 0 |  |  |
Threshold percentage of stockholders' equity |  |  |  |  | 10.00% |  |  |
Borrowings at FHLBC as percentage of total assets |  | 35.00% |  |  | 35.00% |  |  |
Borrowings at FHLBC as percentage of book value of certain mortgage loans |  | 60.00% |  |  | 60.00% |  |  |
FHLBC stock |  | $ 4,500,000 |  |  | $ 4,500,000 | 7,100,000 |  |
Federal Home Loan Bank Chicago ("FHLBC") and Federal Reserve Bank Chicago ("FRBC") stock |  | 19,413,000 |  |  | 19,413,000 | 13,257,000 |  |
Proceeds from term note | $ 30,000,000.0 |  |  |  |  |  |  |
Senior notes |  | 44,559,000 |  |  | 44,559,000 | 44,480,000 |  |
Basis points added to reference rate (as a percent) | 175.00% |  |  |  |  |  |  |
Total borrowings |  | 200,104,000 |  |  | 200,104,000 | 198,876,000 |  |
Asset Pledged as Collateral with Right | Securities sold under repurchase agreements |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  |  |  |  |  | 50,300,000 |  |
Securities available-for-sale, at fair value |  | $ 72,400,000 |  |  | 72,400,000 | 113,000,000.0 |  |
GCFC/ABC Bank |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Debt assumed |  |  |  |  |  |  |  | $ 23,400,000
Balance of borrowings paid off |  |  | $ 5,900,000 |  |  |  |  |
Three Months Secured Overnight Financing Rate |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Basis points added to reference rate (as a percent) |  | 273.00% |  |  |  |  |  |
Securities sold under repurchase agreements |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Total borrowings |  | $ 35,497,000 |  |  | 35,497,000 | 50,337,000 |  |
Securities sold under repurchase agreements | Asset Pledged as Collateral with Right | Securities sold under repurchase agreements |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Investment securities pledged with financial institutions, dollars |  | $ 35,500,000 |  |  | $ 35,500,000 |  |  |
Federal Home Loan Bank Advances |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Borrowings at FHLBC as percentage of book value of certain mortgage loans |  | 60.00% |  |  | 60.00% |  |  |
FHLBC advance amount |  | $ 25.0 |  |  | $ 25.0 | 0 |  |
FHLBC stock |  | 4,500,000 |  |  | 4,500,000 |  |  |
Principal balance of loans collateralized |  | 861,100,000 |  |  | 861,100,000 |  |  |
Combined collateral value |  | 576,700,000 |  |  | 576,700,000 |  |  |
Amount available for additional borrowings |  | 536,700,000 |  |  | 536,700,000 |  |  |
Subordinated debentures |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Total borrowings |  | 59,275,000 |  |  | 59,275,000 | 59,212,000 |  |
Notes Payable to Banks [Member] |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Total borrowings |  | 10,000,000 |  |  | 10,000,000 | 19,074,000 |  |
Junior subordinated debentures |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Total borrowings |  | 25,773,000 |  |  | 25,773,000 | 25,773,000 |  |
Senior Notes [Member] |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  | 5.75% |  |  |  |
Senior notes |  | 44,600,000 |  |  | 44,600,000 | 44,500,000 |  |
Debt Instrument, Term |  |  |  | 10 years |  |  |  |
Interest rate term |  |  |  | 5 years |  |  |  |
Debt issuance costs |  | 441,000 |  |  | $ 441,000 | 520,000 |  |
Amortization period for deferred financing costs |  |  |  |  | 10 years |  |  |
Total borrowings |  | $ 44,559,000 |  |  | $ 44,559,000 | $ 44,480,000 |  |
Debt instrument redemption price, percentage |  |  |  |  | 100.00% |  |  |
Senior Notes [Member] | Debt Instrument, Variable Rate Base LIBOR [Member] |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Basis points added to reference rate (as a percent) |  |  |  | 385.00% |  |  |  |
Term Debt |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Proceeds from term note | $ 20,000,000.0 |  |  |  | $ 10,000,000.0 |  |  |
Debt term | 3 years |  |  |  |  |  |  |
Subordinated Notes Due 2031 |  |  |  |  |  |  |  |
Borrowings |  |  |  |  |  |  |  |
Interest rate (as a percent) |  | 3.50% |  |  | 3.50% |  | 3.50% |
Outstanding, net of deferred issuance costs |  | $ 59,300,000 |  |  | $ 59,300,000 |  |  |
Face amount |  |  |  |  |  |  | $ 60,000,000.0 |

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