Compensation and Benefit Plans - Additional Information (Details)					3 Months Ended		12 Months Ended
	Jan. 28, 2022 shares	Jan. 27, 2022 USD ($) shares	Jan. 01, 2021 USD ($)	Sep. 29, 2017 USD ($) shares	Mar. 31, 2022 USD ($) Executive $ / shares shares	Mar. 31, 2021 USD ($)	Dec. 31, 2021 $ / shares shares	Dec. 31, 2020 $ / shares shares
Compensation And Benefit Plans Disclosure [Line Items]
Additional number of shares					2,073,218		700,896
ESOP related compensation expense including equalization expense | $					$ 373,000	$ 157,000
Number of option grants					0		0
Total remaining unrecognized compensation cost | $					$ 2,500,000
Weighted average period expected to be recognized					69 months
Weighted-average exercise price for options | $ / shares					$ 8.62		$ 12.02	$ 12.02
Weighted average remaining contractual life					6 years 7 months 6 days
Weighted average period expected to be recognized					3 years 6 months
Number of shares exercisable					136,141		94,904
Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage								20.00%
Non-Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage								20.00%
Non-Executive Officers Not Director
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage								20.00%
Restricted Stock Units
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					0
Compensation expense | $					$ 318,000	318,000
Total remaining unrecognized compensation cost | $					$ 320,000
Weighted average period expected to be recognized					69 months
Stock Options
Compensation And Benefit Plans Disclosure [Line Items]
Compensation expense | $					$ 33,000	$ 33,000
Weighted average period expected to be recognized					6 years 6 months	6 years 6 months
2018 Long-Term Incentive Plan
Compensation And Benefit Plans Disclosure [Line Items]
Equity incentive plans, maximum number of shares issuable					1,248,469
Common stock reserved for future issuance					1,248,469
Conversion of issuable stock options to issuable restricted stock ratio					3.0
Number of issuable stock options converted into restricted stock units					462,522
Number of restricted stock units converted from issuable stock options					154,174
Number of grants					674,645
Conversion of issuable stock options to issuable restricted stock					88,119		63,159
2018 Long-Term Incentive Plan | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage								20.00%
2018 Long-Term Incentive Plan | Directors
Compensation And Benefit Plans Disclosure [Line Items]
Vesting percentage								20.00%
Vesting period								10 years
2018 Long-Term Incentive Plan | Stock Options or Stock Appreciation Rights
Compensation And Benefit Plans Disclosure [Line Items]
Common stock reserved for future issuance					891,764
Shares available for future awards					264,357		189,476
2018 Long-Term Incentive Plan | Restricted Stock Units
Compensation And Benefit Plans Disclosure [Line Items]
Common stock reserved for future issuance					356,705
Shares available for future awards					0		0
2018 Long-Term Incentive Plan | Restricted Stock Units | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					322,254
2018 Long-Term Incentive Plan | Restricted Stock Units | Outside Directors
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					148,625
2018 Long-Term Incentive Plan | Restricted Stock Units | Non-Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants					40,000
2018 Long-Term Incentive Plan | Restricted Stock Units | Non-Executive Officers | December 31, 2020
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants								15,000
2018 Long-Term Incentive Plan | Incentive Options | Executive Officers
Compensation And Benefit Plans Disclosure [Line Items]
Number of option grants					119,176
2018 Long-Term Incentive Plan | Incentive Options | Non-Executive Officers | December 31, 2020
Compensation And Benefit Plans Disclosure [Line Items]
Number of stock grants								40,000
2018 Long-Term Incentive Plan | Non-qualified Options | Outside Directors
Compensation And Benefit Plans Disclosure [Line Items]
Number of option grants					44,590
2020 Long-Term Incentive Plan
Compensation And Benefit Plans Disclosure [Line Items]
Number of issuable stock options converted into restricted stock units					45,000
Number of restricted stock units converted from issuable stock options					15,000
Supplemental Executive Retirement Plan
Compensation And Benefit Plans Disclosure [Line Items]
Expense recognized | $					$ 15,000	$ 15,000
Number of key executive under retirement plan | Executive					2
Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Total issued shares	24,711,834
PDL Community Bancorp | Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Conversion of stock	1.3952	977,880
KSOP
Compensation And Benefit Plans Disclosure [Line Items]
Defined contribution plan, maximum annual contributions per employee, amount | $			$ 20,500
Defined contribution plan additional cost | $			$ 6,500
Employer matching contribution percentage			3.00%
Expense recognized | $			$ 27,000
Expenses recognized | $					$ 96,000	$ 87,000
Defined contribution plan, employers matching contribution, annual vesting percentage			100.00%
Defined contribution plan, employer matching contribution, percent of employees' gross pay			20.00%
Defined contribution plan additional cost percentage			20
Number of years discretionary matching and profit sharing contributions			2 years
Number of additional year of service cost			6 years
KSOP | PDL Community Bancorp | Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Additional number of shares		1,097,353
Percentage of Shares Outstanding		4.44
ESOP
Compensation And Benefit Plans Disclosure [Line Items]
Defined contribution plan, employers matching contribution, annual vesting percentage		100.00%
Number of years discretionary matching and profit sharing contributions		3 years
ESOP | PDL Community Bancorp | Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Additional number of shares				723,751
First ESOP Loan
Compensation And Benefit Plans Disclosure [Line Items]
Total issued shares					15,000,000.0
First ESOP Loan | PDL Community Bancorp
Compensation And Benefit Plans Disclosure [Line Items]
Employee stock ownership plan ESOP loan term				15 years
Employee stock ownership plan ESOP interest percentage				2.60
First ESOP Loan | PDL Community Bancorp | Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Aggregate purchase price of common | $				$ 7,200,000
Second ESOP Loan
Compensation And Benefit Plans Disclosure [Line Items]
Total issued shares					15,000,000.0
Second ESOP Loan | PDL Community Bancorp
Compensation And Benefit Plans Disclosure [Line Items]
Employee stock ownership plan ESOP loan term		15 years
Employee stock ownership plan ESOP interest percentage		1.822
Second ESOP Loan | PDL Community Bancorp | Common Stock
Compensation And Benefit Plans Disclosure [Line Items]
Aggregate purchase price of common | $		$ 11,000,000.0