Subordinated Notes and Junior Subordinated Debentures - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount	$ 45,000,000	$ 45,000,000
Fixed-To-Floating Subordinate Notes Mature on July 1, 2030 \| Subordinated Notes
Debt Instrument [Line Items]
Debt instrument, face amount		$ 75,000,000.0
Debt instrument, interest rate		6.00%
Debt instrument, maturity date		Jul. 01, 2030
Debt instrument, redemption, description	As of March 31, 2021, the net liability outstanding of the subordinated notes was $73.4 million The Company may, at its option, redeem the notes, in whole or in part, on a semi-annual basis beginning on July 1, 2025, subject to obtaining the prior approval of the Federal Reserve to the extent such approval is then required.
Debt issuance costs		$ 1,700,000
Debt issuance costs, amortization period		10 years
Net liability outstanding of subordinated notes	$ 73,400,000
Fixed-To-Floating Subordinate Notes Mature on July 1, 2030 \| Subordinated Notes \| Three-Month Secured Overnight Financing Rate Plus 588 Basis Points
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	The subordinated notes bear a fixed interest rate of 6.00% until July 1, 2025 and a floating interest rate equal to a benchmark rate, which is expected to be three-month Secured Overnight Financing Rate plus 588 basis points thereafter until maturity.
Metropolitan Statutory Trust 1
Debt Instrument [Line Items]
Principal amount	$ 35,000,000	$ 35,000,000
Metropolitan Statutory Trust 1 \| Junior Subordinated Debentures
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 17, 2034
Contractual rate	2.97%	3.02%
Accrued interest payable	$ 45,000	$ 45,000
Metropolitan Statutory Trust 1 \| Junior Subordinated Debentures \| Three-month LIBOR
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	Three-month LIBOR + 2.79%
Interest rate spread	2.79%	2.79%
First Evanston Bancorp Trust I
Debt Instrument [Line Items]
Principal amount	$ 10,000,000	$ 10,000,000
First Evanston Bancorp Trust I \| Junior Subordinated Debentures
Debt Instrument [Line Items]
Debt instrument, maturity date	Mar. 15, 2035
Contractual rate	1.96%	2.00%
Accrued interest payable	$ 9,000	$ 9,000
First Evanston Bancorp Trust I \| Junior Subordinated Debentures \| Three-month LIBOR
Debt Instrument [Line Items]
Debt instrument, description of variable rate basis	Three-month LIBOR + 1.78%
Interest rate spread	1.78%	1.78%

Debt issuance costs, amortization period.

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Junior subordinated debenture owed to unconsolidated subsidiary trust, including unamortized discount.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Description of debt redemption features under terms of the debt agreement.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of interest payable on debt, including, but not limited to, trade payables.

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