REGULATORY CAPITAL (Summary of actual capital amounts and ratios) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio (to average assets), Actual Amount	$ 641,082	$ 575,380
Tier 1 leverage ratio (to average assets), Actual Ratio	0.102	0.085
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 250,963	$ 270,863
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	$ 620,462	$ 554,760
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.121	0.141
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 230,879	$ 177,646
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	$ 641,082	$ 575,380
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.125	0.146
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 307,838	$ 236,861
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	$ 686,139	$ 635,002
Total capital (to risk-weighted assets), Actual Ratio	0.134	0.161
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 410,451	$ 315,815
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	0.054%	0.081%
Metropolitan Commercial Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage ratio (to average assets), Actual Amount	$ 628,825	$ 566,835
Tier 1 leverage ratio (to average assets), Actual Ratio	0.100	0.084
Tier 1 leverage ratio (to average assets), For Capital Adequacy Amount	$ 250,920	$ 270,800
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	$ 313,650	$ 338,499
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	$ 628,825	$ 566,835
Tier 1 common equity (to risk-weighted assets), Actual Ratio	0.123	0.144
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 230,815	$ 177,582
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	$ 333,399	$ 256,508
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	$ 628,825	$ 566,835
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.123	0.144
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 307,753	$ 236,777
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	$ 410,337	$ 315,702
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	$ 673,876	$ 601,740
Total capital (to risk-weighted assets), Actual Ratio	0.131	0.152
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 410,337	$ 315,702
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	$ 512,922	$ 394,628
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	0.051%	0.073%

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

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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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