REGULATORY CAPITAL (Summary of actual capital amounts and ratios) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Percentage of capital conversion buffer	0.053%	0.048%
Tier 1 leverage ratio (to average assets), Actual Amount	$ 793,847	$ 722,844
Tier 1 leverage ratio (to average assets), Actual Ratio	0.108	0.106
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 294,141	$ 274,064
Tier 1 leverage ratio (to average assets), For Capital Adequacy Ratio	0.04	0.04
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 773,227	$ 702,224
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.119	0.115
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 291,450	$ 274,867
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	$ 793,847	$ 722,844
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.123	0.118
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 388,600	$ 366,490
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	0.06	0.06
Tier 1 capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Total capital (to risk-weighted assets), Actual Amount	$ 859,129	$ 781,991
Total capital (to risk-weighted assets), Actual Ratio	0.133	0.128
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 518,134	$ 488,653
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	0.08	0.08
Total capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Metropolitan Commercial Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Percentage of capital conversion buffer	0.05%	0.045%
Tier 1 leverage ratio (to average assets), Actual Amount	$ 775,106	$ 703,823
Tier 1 leverage ratio (to average assets), Actual Ratio	0.106	0.103
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 293,513	$ 274,055
Tier 1 leverage ratio (to average assets), For Capital Adequacy Ratio	0.04	0.04
Tier 1 leverage ratio (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 366,892	$ 342,569
Tier 1 leverage ratio (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.05	0.05
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 775,106	$ 703,823
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.12	0.115
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 291,421	$ 274,838
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	$ 420,942	$ 396,989
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	$ 775,106	$ 703,823
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.12	0.115
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 388,562	$ 366,451
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	0.06	0.06
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 518,082	$ 488,601
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.08	0.08
Tier 1 capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025
Total capital (to risk-weighted assets), Actual Amount	$ 840,387	$ 762,969
Total capital (to risk-weighted assets), Actual Ratio	0.13	0.125
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 518,082	$ 488,601
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	0.08	0.08
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 647,603	$ 610,752
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	0.10	0.10
Total capital (to risk-weighted assets), Minimum Capital Conservation Buffer	0.025	0.025

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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-SubTopic 505
-Name Accounting Standards Codification
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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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-Topic 942
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