Loans and Allowance for Loan Losses - Risk category of our loan portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
2021	$ 937,875
2020	672,295
2019	910,302
2018	986,024
2017	722,265
Prior	2,115,071
Revolving Loans Amortized Cost Basis	276,923
Lines of credit converted to term loans	17,350
Total	6,638,105
Pass [Member]
2021	930,645
2020	635,733
2019	821,698
2018	907,825
2017	659,328
Prior	1,967,521
Revolving Loans Amortized Cost Basis	250,068
Lines of credit converted to term loans	15,798
Total	6,188,616
Watch [Member]
2021	7,212
2020	29,314
2019	87,982
2018	68,450
2017	56,083
Prior	131,371
Revolving Loans Amortized Cost Basis	11,199
Lines of credit converted to term loans	562
Total	392,173
Special Mention [Member]
2021	18
2020	2,351
2019	591
2018	4,076
2017	40
Prior	5,123
Revolving Loans Amortized Cost Basis	13,534
Lines of credit converted to term loans	224
Total	25,957
Substandard [Member]
2020	4,897
2019	31
2018	5,673
2017	6,814
Prior	11,056
Revolving Loans Amortized Cost Basis	1,041
Lines of credit converted to term loans	766
Total	30,278
Doubtful [Member]
Revolving Loans Amortized Cost Basis	1,081
Total	1,081
One-To-Four Family - Residential Portfolio Segment [Member]
2021	9,217
2020	30,674
2019	48,965
2018	33,946
2017	26,918
Prior	99,601
Revolving Loans Amortized Cost Basis	11,141
Lines of credit converted to term loans	17,350
Total	277,812
One-To-Four Family - Residential Portfolio Segment [Member] | Pass [Member]
2021	8,917
2020	30,674
2019	48,238
2018	32,105
2017	24,550
Prior	94,407
Revolving Loans Amortized Cost Basis	11,141
Lines of credit converted to term loans	15,798
Total	265,830
One-To-Four Family - Residential Portfolio Segment [Member] | Watch [Member]
2021	300
2019	727
2017	1,249
Prior	1,129
Lines of credit converted to term loans	562
Total	3,967
One-To-Four Family - Residential Portfolio Segment [Member] | Special Mention [Member]
Prior	130
Lines of credit converted to term loans	224
Total	354
One-To-Four Family - Residential Portfolio Segment [Member] | Substandard [Member]
2018	1,841
2017	1,119
Prior	3,935
Lines of credit converted to term loans	766
Total	7,661
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member]
2021	45,767
2020	35,397
2019	68,349
2018	74,580
2017	56,990
Prior	293,853
Total	574,936
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Pass [Member]
2021	45,767
2020	35,397
2019	68,349
2018	74,057
2017	56,310
Prior	286,040
Total	565,920
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Watch [Member]
2017	680
Prior	5,371
Total	6,051
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Special Mention [Member]
Prior	1,130
Total	1,130
One-To-Four Family - Mixed-Use Property Portfolio Segment [Member] | Substandard [Member]
2018	523
Prior	1,312
Total	1,835
Commercial Real Estate
2021	193,177
2020	165,202
2019	262,635
2018	268,887
2017	183,438
Prior	704,036
Total	1,777,375
Commercial Real Estate | Pass [Member]
2021	188,980
2020	161,570
2019	252,976
2018	259,257
2017	180,992
Prior	632,138
Total	1,675,913
Commercial Real Estate | Watch [Member]
2021	4,197
2020	3,632
2019	9,659
2018	9,630
2017	2,446
Prior	70,051
Total	99,615
Commercial Real Estate | Special Mention [Member]
Prior	794
Total	794
Commercial Real Estate | Substandard [Member]
Prior	1,053
Total	1,053
Construction Portfolio Segment [Member]
2021	5,022
2020	11,515
2019	14,800
2018	7,755
2017	4,524
Revolving Loans Amortized Cost Basis	15,857
Total	59,473
Construction Portfolio Segment [Member] | Pass [Member]
2021	5,022
2020	11,515
2019	14,800
2018	1,993
Revolving Loans Amortized Cost Basis	15,857
Total	49,187
Construction Portfolio Segment [Member] | Watch [Member]
2018	4,033
2017	4,524
Total	8,557
Construction Portfolio Segment [Member] | Special Mention [Member]
2018	856
Total	856
Construction Portfolio Segment [Member] | Substandard [Member]
2018	873
Total	873
Multi-family Residential Portfolio Segment [Member]
2021	315,464
2020	238,873
2019	334,068
2018	441,121
2017	348,770
Prior	834,916
Revolving Loans Amortized Cost Basis	6,015
Total	2,519,227
Multi-family Residential Portfolio Segment [Member] | Pass [Member]
2021	314,345
2020	236,768
2019	330,360
2018	426,016
2017	347,616
Prior	823,451
Revolving Loans Amortized Cost Basis	5,864
Total	2,484,420
Multi-family Residential Portfolio Segment [Member] | Watch [Member]
2021	1,119
2020	1,136
2019	3,708
2018	12,180
2017	1,154
Prior	7,702
Total	26,999
Multi-family Residential Portfolio Segment [Member] | Special Mention [Member]
2020	969
2018	797
Prior	3,021
Total	4,787
Multi-family Residential Portfolio Segment [Member] | Substandard [Member]
2018	2,128
Prior	742
Revolving Loans Amortized Cost Basis	151
Total	3,021
Commercial Business Secured By Portfolio Segment [member]
2021	176,376
2020	115,214
2019	90,106
2018	64,033
2017	34,790
Prior	142,613
Total	623,132
Commercial Business Secured By Portfolio Segment [member] | Pass [Member]
2021	176,376
2020	92,336
2019	38,215
2018	45,348
2017	22,644
Prior	92,725
Total	467,644
Commercial Business Secured By Portfolio Segment [member] | Watch [Member]
2020	22,878
2019	51,300
2018	18,685
2017	12,146
Prior	46,279
Total	151,288
Commercial Business Secured By Portfolio Segment [member] | Special Mention [Member]
2019	591
Total	591
Commercial Business Secured By Portfolio Segment [member] | Substandard [Member]
Prior	3,609
Total	3,609
Commercial Business Portfolio Segment [Member]
2021	129,157
2020	58,386
2019	90,593
2018	91,595
2017	63,191
Prior	37,431
Revolving Loans Amortized Cost Basis	243,814
Total	714,167
Commercial Business Portfolio Segment [Member] | Pass [Member]
2021	127,543
2020	50,439
2019	68,031
2018	67,520
2017	26,589
Prior	37,016
Revolving Loans Amortized Cost Basis	217,110
Total	594,248
Commercial Business Portfolio Segment [Member] | Watch [Member]
2021	1,596
2020	1,668
2019	22,531
2018	21,344
2017	31,819
Prior	15
Revolving Loans Amortized Cost Basis	11,199
Total	90,172
Commercial Business Portfolio Segment [Member] | Special Mention [Member]
2021	18
2020	1,382
2018	2,423
2017	40
Revolving Loans Amortized Cost Basis	13,534
Total	17,397
Commercial Business Portfolio Segment [Member] | Substandard [Member]
2020	4,897
2019	31
2018	308
2017	4,743
Prior	400
Revolving Loans Amortized Cost Basis	890
Total	11,269
Commercial Business Portfolio Segment [Member] | Doubtful [Member]
Revolving Loans Amortized Cost Basis	1,081
Total	1,081
Small Business Administration Portfolio Segment [Member]
2021	63,695
2020	17,034
2019	786
2018	4,107
2017	3,644
Prior	2,570
Total	91,836
Small Business Administration Portfolio Segment [Member] | Pass [Member]
2021	63,695
2020	17,034
2019	729
2018	1,529
2017	627
Prior	1,693
Total	85,307
Small Business Administration Portfolio Segment [Member] | Watch [Member]
2019	57
2018	2,578
2017	2,065
Prior	824
Total	5,524
Small Business Administration Portfolio Segment [Member] | Special Mention [Member]
Prior	48
Total	48
Small Business Administration Portfolio Segment [Member] | Substandard [Member]
2017	952
Prior	5
Total	957
Other Portfolio Segment [Member]
Prior	51
Revolving Loans Amortized Cost Basis	96
Total	147
Other Portfolio Segment [Member] | Pass [Member]
Prior	51
Revolving Loans Amortized Cost Basis	96
Total	147
Consumer Portfolio Segment [Member]
Mortgage Loans in Process of Foreclosure, Amount	$ 8,700	$ 5,900