Share-Based Compensation Arrangement By Share Based Payment Award, Award Vesting Period, Term Of Measurement Period

No definition available.

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- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Grant Date Fair Value

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No definition available.

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- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Vesting, Period After Grant

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- Definition

Share-Based Payment Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Percentage Of Target Awarded

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No definition available.

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

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- Definition

This item represents the amount of cash contributions during the period made by the entity to the Employee Stock Ownership Plan (ESOP).

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The amount of plan compensation cost recognized during the period.

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The amount reported as a liability as of the balance sheet date by the entity (the employer) of the loan made by a third-party lender directly to the ESOP.

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- Definition

Sum of the allocated, committed-to-be-released and suspense shares of the entity held by the plan.

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Weighted average purchase price of capital shares purchased through an employee stock ownership plan.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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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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Number of shares authorized for issuance under share-based payment arrangement.

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Gross number of share options (or share units) granted during the period.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Aug. 25, 2022	Dec. 31, 2025	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unallocated common stock held by ESOP (in shares)		2,281,800	2,281,800
Price per share, ESOP (in usd per share)		$ 10
Remaining principal on ESOP loan		$ 19,300	$ 19,900
Purchase of common shares by the ESOP		677	655
ESOP and stock-based compensation expense		$ 871	$ 892
Granted (in shares)		38,500
Forfeited (in shares)		136,483
Expected future expense of non-vested options		$ 4,100
Restricted Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected future expense of non-vested RSUs		$ 5,300
Expected period of recognition (in years)		3 years 6 months
Stock option expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected period of recognition (in years)		3 years 3 months 18 days
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares authorized for grant (in shares)	3,993,150
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Restricted Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares authorized for grant (in shares)	1,140,900
Initial period before vesting begins (in years)	1 year
Granted (in shares)		38,500	213,880
Aggregate grant date fair value		$ 367	$ 2,100
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Restricted Stock \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)		3 years	1 year
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Restricted Stock \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)		5 years	6 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Restricted Stock \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)	5 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Restricted Stock \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)	7 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Stock option expense
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares authorized for grant (in shares)	2,852,250
Initial period before vesting begins (in years)	1 year
Expiration period of options(in years)	10 years
Stock options granted (in shares)			96,266
Expected life of stock options (in years)			6 years 6 months
Risk free interest rate			4.11%
Expected volatility rate			32.63%
Expected dividend yield			0.82%
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Stock option expense \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)	5 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Stock option expense \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)	7 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Performance Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting service period (in years)		4 years
Granted (in shares)		0	193,070
Aggregate grant date fair value			$ 1,800
Term of measurement period for PSUs (in years)		3 years
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Performance Shares \| Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of target awarded		0.00%
Blue Foundry Bancorp 2022 Equity Incentive Plan (Equity Plan) \| Performance Shares \| Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of target awarded		100.00%