Loans and Allowance for Loan Losses - Non-Accrual at Amortized Cost (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Total Non-accrual amortized cost	$ 20,947	$ 28,026
Non-Accrual with no related Allowance	16,880
Interest income recognized	58
Loans ninety days or more past due and still accruing:	2,748	445
Multi-family Residential Portfolio Segment [Member]
Total Non-accrual amortized cost	2,576	2,723
Non-Accrual with no related Allowance	2,576
Loans ninety days or more past due and still accruing:	201
Commercial Real Estate
Total Non-accrual amortized cost	1,766	2,714
Non-Accrual with no related Allowance	1,766
Loans ninety days or more past due and still accruing:	2,547	445
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
Total Non-accrual amortized cost	1,706	1,704
Non-Accrual with no related Allowance	1,706
One-To-Four Family - Residential Portfolio Segment [Member]
Total Non-accrual amortized cost	5,313	9,992
Non-Accrual with no related Allowance	5,313
Small Business Administration Portfolio Segment [Member]
Total Non-accrual amortized cost	1,168	1,169
Non-Accrual with no related Allowance	1,168
Taxi Medallion Portfolio Segment [Member]
Total Non-accrual amortized cost	2,758	2,318
Non-Accrual with no related Allowance	2,758
Commercial Business and Other Portfolio Segment [Member]
Total Non-accrual amortized cost	5,660	$ 7,406
Non-Accrual with no related Allowance	1,593
Interest income recognized	$ 58

Amount of financing receivable on nonaccrual status at amortized cost.

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Amount of interest income on financing receivable on nonaccrual status.

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Amount of financing receivable on nonaccrual status with no allowance for credit loss.

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Amount of financing receivable 90 days or more past due and still accruing.

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