Loans Receivable and Allowance for Credit Losses (Summary of Loans Receivable by Credit Quality Risk Rating Indicator) (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 481,919	$ 1,654,769
2021	1,774,090	1,541,098
2020	1,521,153	1,329,195
2019	1,323,513	878,030
2018	854,298	850,574
Prior to 2018	2,964,896	2,638,782
Revolving Loans	660,946	602,877
Revolving loans to term loans	93,105	98,554
Total gross loans	9,673,920	9,593,879
Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,232
2021	0	7,586
2020	1,408	37,057
2019	40,110	68,440
2018	87,037	51,092
Prior to 2018	181,421	178,234
Revolving Loans	23,943	23,935
Revolving loans to term loans	2,306	4,070
Total gross loans	336,225	371,646
Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,232
2021	0	6,411
2020	967	31,522
2019	30,471	25,559
2018	71,265	37,825
Prior to 2018	70,376	68,043
Revolving Loans	2,563	9,508
Revolving loans to term loans	1,393	2,249
Total gross loans	177,035	182,349
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	1,175
2020	441	5,535
2019	9,639	42,881
2018	15,772	13,267
Prior to 2018	111,045	110,191
Revolving Loans	21,380	14,427
Revolving loans to term loans	913	1,821
Total gross loans	159,190	189,297
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	481,919	1,653,537
2021	1,774,090	1,533,512
2020	1,519,745	1,292,138
2019	1,283,403	809,590
2018	767,261	799,482
Prior to 2018	2,783,475	2,460,548
Revolving Loans	637,003	578,942
Revolving loans to term loans	90,799	94,484
Total gross loans	9,337,695	9,222,233
Mortgage Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
2022	348,255	1,212,473
2021	1,266,540	1,311,065
2020	1,284,516	1,117,397
2019	1,086,094	693,305
2018	659,584	655,036
Prior to 2018	2,433,427	1,943,634
Revolving Loans	109,444	106,391
Revolving loans to term loans	38,145	38,270
Total gross loans	7,226,005	7,077,571
Mortgage Portfolio Segment | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	4,188
2020	1,277	28,724
2019	30,024	59,201
2018	78,013	20,925
Prior to 2018	49,887	71,243
Revolving Loans	774	1,893
Revolving loans to term loans	0	0
Total gross loans	159,975	186,174
Mortgage Portfolio Segment | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	3,749
2020	838	28,706
2019	29,642	22,296
2018	68,038	13,407
Prior to 2018	16,967	27,373
Revolving Loans	0	1,094
Revolving loans to term loans	0	0
Total gross loans	115,485	96,625
Mortgage Portfolio Segment | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	439
2020	439	18
2019	382	36,905
2018	9,975	7,518
Prior to 2018	32,920	43,870
Revolving Loans	774	799
Revolving loans to term loans	0	0
Total gross loans	44,490	89,549
Mortgage Portfolio Segment | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	348,255	1,212,473
2021	1,266,540	1,306,877
2020	1,283,239	1,088,673
2019	1,056,070	634,104
2018	581,571	634,111
Prior to 2018	2,383,540	1,872,391
Revolving Loans	108,670	104,498
Revolving loans to term loans	38,145	38,270
Total gross loans	7,066,030	6,891,397
Mortgage Portfolio Segment | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
2022	45,614	229,106
2021	225,105	235,949
2020	228,755	113,206
2019	109,721	67,773
2018	63,007	76,769
Prior to 2018	522,411	479,835
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	1,194,613	1,202,638
Mortgage Portfolio Segment | Residential | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	280
2018	280	863
Prior to 2018	9,072	9,003
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	9,352	10,146
Mortgage Portfolio Segment | Residential | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	697
Prior to 2018	1,354	434
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	1,354	1,131
Mortgage Portfolio Segment | Residential | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	280
2018	280	166
Prior to 2018	7,718	8,569
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	7,998	9,015
Mortgage Portfolio Segment | Residential | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Residential | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Residential | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	45,614	229,106
2021	225,105	235,949
2020	228,755	113,206
2019	109,721	67,493
2018	62,727	75,906
Prior to 2018	513,339	470,832
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	1,185,261	1,192,492
Mortgage Portfolio Segment | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022	235,572	655,105
2021	662,441	602,654
2020	603,388	618,302
2019	601,497	355,221
2018	341,000	447,956
Prior to 2018	1,355,902	1,013,770
Revolving Loans	106,749	103,511
Revolving loans to term loans	30,667	30,851
Total gross loans	3,937,216	3,827,370
Mortgage Portfolio Segment | Commercial | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	2,624
2020	838	28,724
2019	28,703	56,556
2018	56,354	17,009
Prior to 2018	36,578	61,024
Revolving Loans	774	1,893
Revolving loans to term loans	0	0
Total gross loans	123,247	167,830
Mortgage Portfolio Segment | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	2,624
2020	838	28,706
2019	28,703	22,296
2018	49,024	9,657
Prior to 2018	13,930	26,668
Revolving Loans	0	1,094
Revolving loans to term loans	0	0
Total gross loans	92,495	91,045
Mortgage Portfolio Segment | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	18
2019	0	34,260
2018	7,330	7,352
Prior to 2018	22,648	34,356
Revolving Loans	774	799
Revolving loans to term loans	0	0
Total gross loans	30,752	76,785
Mortgage Portfolio Segment | Commercial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Commercial | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Commercial | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	235,572	655,105
2021	662,441	600,030
2020	602,550	589,578
2019	572,794	298,665
2018	284,646	430,947
Prior to 2018	1,319,324	952,746
Revolving Loans	105,975	101,618
Revolving loans to term loans	30,667	30,851
Total gross loans	3,813,969	3,659,540
Mortgage Portfolio Segment | Multi-Family
Financing Receivable, Credit Quality Indicator [Line Items]
2022	51,221	154,419
2021	154,053	295,155
2020	284,879	166,558
2019	155,014	173,583
2018	193,026	120,707
Prior to 2018	552,710	449,926
Revolving Loans	2,695	2,880
Revolving loans to term loans	1,163	1,169
Total gross loans	1,394,761	1,364,397
Mortgage Portfolio Segment | Multi-Family | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	439
2020	439	0
2019	0	0
2018	0	3,053
Prior to 2018	4,237	1,216
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	4,676	4,708
Mortgage Portfolio Segment | Multi-Family | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	3,053
Prior to 2018	1,683	271
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	1,683	3,324
Mortgage Portfolio Segment | Multi-Family | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	439
2020	439	0
2019	0
2018	0	0
Prior to 2018	2,554	945
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	2,993	1,384
Mortgage Portfolio Segment | Multi-Family | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Multi-Family | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Multi-Family | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	51,221	154,419
2021	154,053	294,716
2020	284,440	166,558
2019	155,014	173,583
2018	193,026	117,654
Prior to 2018	548,473	448,710
Revolving Loans	2,695	2,880
Revolving loans to term loans	1,163	1,169
Total gross loans	1,390,085	1,359,689
Mortgage Portfolio Segment | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022	15,848	173,843
2021	224,941	177,307
2020	167,494	219,331
2019	219,862	96,728
2018	62,551	9,604
Prior to 2018	2,404	103
Revolving Loans	0	0
Revolving loans to term loans	6,315	6,250
Total gross loans	699,415	683,166
Mortgage Portfolio Segment | Construction | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	1,125
2020	0	0
2019	1,321	2,365
2018	21,379	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	22,700	3,490
Mortgage Portfolio Segment | Construction | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	1,125
2020	0	0
2019	939	0
2018	19,014	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	19,953	1,125
Mortgage Portfolio Segment | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	382	2,365
2018	2,365	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	2,747	2,365
Mortgage Portfolio Segment | Construction | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Construction | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Mortgage Portfolio Segment | Construction | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	15,848	173,843
2021	224,941	176,182
2020	167,494	219,331
2019	218,541	94,363
2018	41,172	9,604
Prior to 2018	2,404	103
Revolving Loans
Revolving loans to term loans	6,315	6,250
Total gross loans	676,715	679,676
Commercial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2022	125,998	417,156
2021	484,075	225,530
2020	233,078	187,526
2019	217,599	163,563
2018	174,768	179,732
Prior to 2018	424,774	594,419
Revolving Loans	432,084	377,108
Revolving loans to term loans	38,950	43,832
Total gross loans	2,131,326	2,188,866
Commercial Loans | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,232
2021	0	3,398
2020	131	8,333
2019	10,086	9,123
2018	8,910	30,165
Prior to 2018	130,518	105,368
Revolving Loans	23,163	22,011
Revolving loans to term loans	2,218	3,976
Total gross loans	175,026	183,606
Commercial Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	1,232
2021	0	2,662
2020	129	2,816
2019	829	3,263
2018	3,227	24,418
Prior to 2018	53,407	40,561
Revolving Loans	2,563	8,389
Revolving loans to term loans	1,305	2,155
Total gross loans	61,460	85,496
Commercial Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	736
2020	2	5,517
2019	9,257	5,860
2018	5,683	5,747
Prior to 2018	77,111	64,807
Revolving Loans	20,600	13,622
Revolving loans to term loans	913	1,821
Total gross loans	113,566	98,110
Commercial Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Commercial Loans | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Commercial Loans | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	125,998	415,924
2021	484,075	222,132
2020	232,947	179,193
2019	207,513	154,440
2018	165,858	149,567
Prior to 2018	294,256	489,051
Revolving Loans	408,921	355,097
Revolving loans to term loans	36,732	39,856
Total gross loans	1,956,300	2,005,260
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2022	7,666	25,140
2021	23,475	4,503
2020	3,559	24,272
2019	19,820	21,162
2018	19,946	15,806
Prior to 2018	106,695	100,729
Revolving Loans	119,418	119,378
Revolving loans to term loans	16,010	16,452
Total gross loans	316,589	327,442
Consumer Loans | Total classified and criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	116
2018	114	2
Prior to 2018	1,016	1,623
Revolving Loans	6	31
Revolving loans to term loans	88	94
Total gross loans	1,224	1,866
Consumer Loans | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	2	109
Revolving Loans	0	25
Revolving loans to term loans	88	94
Total gross loans	90	228
Consumer Loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	116
2018	114	2
Prior to 2018	1,014	1,514
Revolving Loans	6	6
Revolving loans to term loans	0	0
Total gross loans	1,134	1,638
Consumer Loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Consumer Loans | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior to 2018	0	0
Revolving Loans	0	0
Revolving loans to term loans	0	0
Total gross loans	0	0
Consumer Loans | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
2022	7,666	25,140
2021	23,475	4,503
2020	3,559	24,272
2019	19,820	21,046
2018	19,832	15,804
Prior to 2018	105,679	99,106
Revolving Loans	119,412	119,347
Revolving loans to term loans	15,922	16,358
Total gross loans	$ 315,365	$ 325,576