REGULATORY CAPITAL (Summary of actual capital amounts and ratios) (Details) $ in Thousands	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount	$ 635,002	$ 410,959
Total capital (to risk-weighted assets), Actual Ratio	16.1	12.7
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 315,815
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.0
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 554,760	$ 324,592
Tier 1 common equity (to risk-weighted assets), Actual Ratio	14.1	10.1
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 177,646
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Ratio	4.50%
Tier 1 capital (to risk-weighted assets), Actual Amount	$ 575,380	$ 350,714
Tier 1 capital (to risk-weighted assets), Actual Ratio	14.6	10.9
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 236,861
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	6.0
Tier 1 capital (to average assets), Actual Amount	$ 575,380	$ 350,714
Tier 1 capital (to average assets), Actual Ratio	8.5	8.5
Tier 1 capital (to average assets), For Capital Adequacy Amount	$ 270,863
Tier 1 capital (to average assets), For Capital Adequacy Ratio	4.0
Total capital (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Amount		$ 257,941
Total capital (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Ratio		8.00%
Tier 1 common equity (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Amount		$ 145,092
Tier 1 common equity (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Ratio		4.50%
Tier 1 capital (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Amount		$ 193,456
Tier 1 capital (to risk-weighted assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Ratio		6.00%
Tier 1 capital (to average assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Amount		$ 165,767
Tier 1 capital (to average assets), Minimum for Capital Adequacy plus Capital Conservation Buffer Ratio		4.00%
Metropolitan Commercial Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount	$ 601,740	$ 410,295
Total capital (to risk-weighted assets), Actual Ratio	15.2	12.7
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 315,702	$ 257,827
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.0	8.0
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 394,628	$ 322,284
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	10.0	10.0
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 566,835	$ 374,712
Tier 1 common equity (to risk-weighted assets), Actual Ratio	14.4	11.6
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 177,582	$ 145,028
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Ratio	4.50%	4.50%
Tier 1 common equity (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 256,508	$ 209,485
Tier 1 common equity (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	6.50%	6.50%
Tier 1 capital (to risk-weighted assets), Actual Amount	$ 566,835	$ 374,712
Tier 1 capital (to risk-weighted assets), Actual Ratio	14.4	11.6
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 236,777	$ 193,370
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	6.0	6.0
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 315,702	$ 257,827
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	8.0	8.0
Tier 1 capital (to average assets), Actual Amount	$ 566,835	$ 374,712
Tier 1 capital (to average assets), Actual Ratio	8.4	9.0
Tier 1 capital (to average assets), For Capital Adequacy Amount	$ 270,800	$ 165,704
Tier 1 capital (to average assets), For Capital Adequacy Ratio	4.0	4.0
Tier 1 capital (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 338,499	$ 207,130
Tier 1 capital (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	5.0	5.0

The amount of total capital minimum for capital adequacy plus capital conservation buffer.

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Tier 1 leverage minimum for capital adequacy plus capital conservation buffer as defined in the regulations.

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

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