REGULATORY CAPITAL (Summary of actual capital amounts and ratios) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio (to average assets), Actual Amount	$ 722,844	$ 641,082
Tier 1 leverage ratio (to average assets), Actual Ratio	0.106	0.102
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 274,064	$ 250,963
Tier 1 leverage ratio (to average assets), For Capital Adequacy Ratio	0.040	0.040
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 702,224	$ 620,462
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.115	0.121
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 274,867	$ 230,879
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Ratio	0.045	0.045
Tier 1 common equity (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Tier 1 capital (to risk-weighted assets), Actual Amount	$ 722,844	$ 641,082
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.118	0.125
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 366,490	$ 307,838
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	0.060	0.060
Tier 1 capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Total capital (to risk-weighted assets), Actual Amount	$ 781,991	$ 686,139
Total capital (to risk-weighted assets), Actual Ratio	0.128	0.134
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 488,653	$ 410,451
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	0.080	0.080
Total capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Percentage of capital conversion buffer	4.80%	5.40%
Metropolitan Commercial Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio (to average assets), Actual Amount	$ 703,823	$ 628,825
Tier 1 leverage ratio (to average assets), Actual Ratio	0.103	0.100
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 274,055	$ 250,920
Tier 1 leverage ratio (to average assets), For Capital Adequacy Ratio	0.040	0.040
Tier 1 leverage ratio (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 342,569	$ 313,650
Tier 1 leverage ratio (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.050	0.050
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 703,823	$ 628,825
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.115	0.123
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 274,838	$ 230,815
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Ratio	0.045	0.045
Tier 1 common equity (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 396,989	$ 333,399
Tier 1 common equity (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.065	0.065
Tier 1 common equity (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Tier 1 capital (to risk-weighted assets), Actual Amount	$ 703,823	$ 628,825
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.115	0.123
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 366,451	$ 307,753
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	0.060	0.060
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 488,601	$ 410,337
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.080	0.080
Tier 1 capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Total capital (to risk-weighted assets), Actual Amount	$ 762,969	$ 673,876
Total capital (to risk-weighted assets), Actual Ratio	0.125	0.131
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 488,601	$ 410,337
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	0.080	0.080
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 610,752	$ 512,922
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.100	0.100
Total capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Percentage of capital conversion buffer	4.50%	5.10%

Percentage of common equity tier one capital required for capital adequacy to risk weighted assets ratio.

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Percentage of capital conversion buffer as at the end of the reporting period.

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Amount of total capital as defined by regulatory framework.

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

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Amount of Common Equity Tier 1 risk-based capital as defined by regulatory framework.

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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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