REGULATORY CAPITAL (Summary of actual capital amounts and ratios) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount	$ 319,053	$ 287,039
Total capital (to risk-weighted assets), Actual Ratio	16.90%	19.90%
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 151,053	$ 115,636
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.00%	8.00%
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 249,655	$ 221,803
Tier 1 common equity (to risk-weighted assets), Actual Ratio	13.20%	15.30%
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 84,968	$ 65,045
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Ratio	4.50%	4.50%
Tier 1 capital (to risk-weighted assets), Actual Amount	$ 275,158	$ 247,305
Tier 1 capital (to risk-weighted assets), Actual Ratio	14.60%	17.10%
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 113,290	$ 86,726
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	6.00%	6.00%
Tier 1 capital (to average assets), Actual Amount	$ 275,158	$ 247,305
Tier 1 capital (to average assets), Actual Ratio	13.70%	13.70%
Tier 1 capital (to average assets), For Capital Adequacy Amount	$ 80,244	$ 72,206
Tier 1 capital (to average assets), For Capital Adequacy Ratio	4.00%	4.00%
Metropolitan Commercial Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual Amount	$ 314,226	$ 280,317
Total capital (to risk-weighted assets), Actual Ratio	16.70%	19.40%
Total capital (to risk-weighted assets), For Capital Adequacy Amount	$ 150,900	$ 115,523
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 188,625	$ 144,403
Total capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	10.00%	10.00%
Tier 1 common equity (to risk-weighted assets), Actual Amount	$ 294,880	$ 265,076
Tier 1 common equity (to risk-weighted assets), Actual Ratio	15.60%	18.40%
Tier 1 common equity (to risk-weighted assets), For Capital Adequacy Amount	$ 84,881	$ 64,981
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	$ 122,606	$ 93,862
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	$ 294,880	$ 265,076
Tier 1 capital (to risk-weighted assets), Actual Ratio	15.60%	18.40%
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Amount	$ 113,175	$ 86,642
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Ratio	6.00%	6.00%
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 150,900	$ 115,523
Tier 1 capital (to risk-weighted assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	8.00%	8.00%
Tier 1 capital (to average assets), Actual Amount	$ 294,880	$ 265,076
Tier 1 capital (to average assets), Actual Ratio	14.70%	14.70%
Tier 1 capital (to average assets), For Capital Adequacy Amount	$ 80,050	$ 72,099
Tier 1 capital (to average assets), For Capital Adequacy Ratio	4.00%	4.00%
Tier 1 capital (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Amount	$ 100,063	$ 90,124
Tier 1 capital (to average assets), To be Well Capitalized under Prompt Corrective Action Regulations Ratio	5.00%	5.00%

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

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Percentage of common equity tier one capital required to be well capitalized to risk weighted assets ratio.

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Amount of Common Equity Tier One Risk-based Capital, as defined by regulatory framework.

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Percentage of Common Equity Tier One Risk-based Capital to total risk-weighted assets, as defined by regulatory framework.

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Amount of Common Equity Tier 1 Risk-based Capital required to be categorized as adequately capitalized under regulatory framework for prompt corrective action.

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Amount of Common Equity Tier 1 Risk-based Capital required to be categorized as well-capitalized under regulatory framework for prompt corrective action.

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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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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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