Loans Receivable - Loans Based on Credit Quality Indicators (Details) $ in Thousands	Mar. 31, 2022 USD ($)
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	$ 1,296,933
2021	2,560,967
2020	1,376,756
2019	621,592
2018	539,381
Prior to 2018	1,355,819
Revolving Loans	1,354,925
Revolving to Term Loans	84
Total Loans	9,106,457
Commercial loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	1,293,479
2021	2,545,335
2020	1,341,765
2019	548,023
2018	500,357
Prior to 2018	1,295,134
Revolving Loans	1,258,117
Revolving to Term Loans	84
Total Loans	8,782,294
Commercial loans \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	3,454
2021	2,185
2020	4,494
2019	31,333
2018	32,952
Prior to 2018	10,388
Revolving Loans	35,150
Revolving to Term Loans	0
Total Loans	119,956
Commercial loans \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	13,447
2020	30,497
2019	42,236
2018	6,072
Prior to 2018	50,297
Revolving Loans	61,658
Revolving to Term Loans	0
Total Loans	204,207
Commercial loans \| Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	401,130
2021	747,291
2020	424,836
2019	143,051
2018	198,399
Prior to 2018	441,715
Revolving Loans	21,235
Revolving to Term Loans	0
Total Loans	2,377,657
Commercial loans \| Multi-family \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	401,130
2021	747,291
2020	423,091
2019	143,051
2018	197,750
Prior to 2018	440,126
Revolving Loans	21,235
Revolving to Term Loans	0
Total Loans	2,373,674
Commercial loans \| Multi-family \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	1,745
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	1,745
Commercial loans \| Multi-family \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	649
Prior to 2018	1,589
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,238
Commercial loans \| Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	438,223
2021	665,379
2020	421,081
2019	357,426
2018	295,820
Prior to 2018	626,639
Revolving Loans	4,060
Revolving to Term Loans	0
Total Loans	2,808,628
Commercial loans \| Commercial real estate \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	438,223
2021	665,379
2020	412,828
2019	289,728
2018	261,937
Prior to 2018	571,942
Revolving Loans	2,974
Revolving to Term Loans	0
Total Loans	2,643,011
Commercial loans \| Commercial real estate \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	25,548
2018	32,952
Prior to 2018	10,388
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	68,888
Commercial loans \| Commercial real estate \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	8,253
2019	42,150
2018	931
Prior to 2018	44,309
Revolving Loans	1,086
Revolving to Term Loans	0
Total Loans	96,729
Commercial loans \| Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	169,459
2021	549,185
2020	194,583
2019	51,787
2018	32,953
Prior to 2018	239,696
Revolving Loans	1,259,261
Revolving to Term Loans	84
Total Loans	2,497,008
Commercial loans \| Commercial & industrial \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	166,005
2021	535,738
2020	169,933
2019	45,916
2018	28,461
Prior to 2018	237,637
Revolving Loans	1,163,539
Revolving to Term Loans	84
Total Loans	2,347,313
Commercial loans \| Commercial & industrial \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	3,454
2021	0
2020	2,749
2019	5,785
2018	0
Prior to 2018	0
Revolving Loans	35,150
Revolving to Term Loans	0
Total Loans	47,138
Commercial loans \| Commercial & industrial \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	13,447
2020	21,901
2019	86
2018	4,492
Prior to 2018	2,059
Revolving Loans	60,572
Revolving to Term Loans	0
Total Loans	102,557
Commercial loans \| Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	243,483
2021	519,391
2020	306,309
2019	58,463
2018	374
Prior to 2018	16,314
Revolving Loans	67,769
Revolving to Term Loans	0
Total Loans	1,212,103
Commercial loans \| Construction \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	243,483
2021	517,206
2020	305,966
2019	58,463
2018	374
Prior to 2018	16,314
Revolving Loans	67,769
Revolving to Term Loans	0
Total Loans	1,209,575
Commercial loans \| Construction \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	2,185
2020	0
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,185
Commercial loans \| Construction \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	343
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	343
Commercial loans \| Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	44,638
2021	79,721
2020	29,947
2019	10,865
2018	11,835
Prior to 2018	31,455
Revolving Loans	2,600
Revolving to Term Loans	0
Total Loans	211,061
Commercial loans \| Land - acquisition & development \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	44,638
2021	79,721
2020	29,947
2019	10,865
2018	11,835
Prior to 2018	29,115
Revolving Loans	2,600
Revolving to Term Loans	0
Total Loans	208,721
Commercial loans \| Land - acquisition & development \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	2,340
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,340
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	850,202
2021	1,816,690
2020	858,436
2019	359,183
2018	331,112
Prior to 2018	1,761,755
Revolving Loans	182,203
Revolving to Term Loans	272
Total Loans	6,159,853
Consumer loans \| Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	850,200
2021	1,816,036
2020	857,485
2019	358,440
2018	330,943
Prior to 2018	1,741,477
Revolving Loans	181,799
Revolving to Term Loans	164
Total Loans	6,136,544
Consumer loans \| 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	654
2020	51
2019	6
2018	0
Prior to 2018	3,279
Revolving Loans	90
Revolving to Term Loans	108
Total Loans	4,188
Consumer loans \| 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	2
2021	0
2020	387
2019	361
2018	0
Prior to 2018	2,072
Revolving Loans	4
Revolving to Term Loans	0
Total Loans	2,826
Consumer loans \| 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	513
2019	376
2018	169
Prior to 2018	14,927
Revolving Loans	310
Revolving to Term Loans	0
Total Loans	16,295
Consumer loans \| Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	48,348
2021	255,969
2020	36,912
2019	2,184
2018	700
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	344,113
Consumer loans \| Construction \| Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	48,348
2021	255,534
2020	36,447
2019	2,184
2018	700
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	343,213
Consumer loans \| Construction \| 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	435
2020	0
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	435
Consumer loans \| Construction \| 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	465
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	465
Consumer loans \| Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	767,151
2021	1,479,787
2020	791,384
2019	350,391
2018	298,428
Prior to 2018	1,731,504
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	5,418,645
Consumer loans \| Single-family residential \| Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	767,151
2021	1,479,568
2020	790,997
2019	349,688
2018	298,259
Prior to 2018	1,711,718
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	5,397,381
Consumer loans \| Single-family residential \| 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	219
2020	0
2019	0
2018	0
Prior to 2018	3,066
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	3,285
Consumer loans \| Single-family residential \| 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	387
2019	361
2018	0
Prior to 2018	2,037
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,785
Consumer loans \| Single-family residential \| 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	342
2018	169
Prior to 2018	14,683
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	15,194
Consumer loans \| Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	34,562
2021	70,609
2020	22,061
2019	6,202
2018	3,727
Prior to 2018	16,388
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	153,549
Consumer loans \| Land - consumer lot loans \| Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	34,562
2021	70,609
2020	21,962
2019	6,202
2018	3,727
Prior to 2018	16,110
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	153,172
Consumer loans \| Land - consumer lot loans \| 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	51
2019	0
2018	0
Prior to 2018	16
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	67
Consumer loans \| Land - consumer lot loans \| 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	19
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	19
Consumer loans \| Land - consumer lot loans \| 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	48
2019	0
2018	0
Prior to 2018	243
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	291
Consumer loans \| HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	5,319
Revolving Loans	170,338
Revolving to Term Loans	272
Total Loans	175,929
Consumer loans \| HELOC \| Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	5,154
Revolving Loans	169,939
Revolving to Term Loans	164
Total Loans	175,257
Consumer loans \| HELOC \| 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	150
Revolving Loans	89
Revolving to Term Loans	108
Total Loans	347
Consumer loans \| HELOC \| 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0

Loans Receivable - Loans Based on Credit Quality Indicators (Details)
$ in Thousands

Mar. 31, 2022

USD ($)

Commercial loans

Financing Receivable, Credit Quality Indicator [Line Items]

$ 1,296,933

2,560,967

1,376,756