Loans Receivable and Allowance for Credit Losses - Credit Risk Ratings and/or Vintage Years for Loans Held-for-Investment by Portfolio Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	$ 12,464,897	$ 10,680,884
One Year before Current Fiscal Year	8,204,714	6,294,357
Two Years before Current Fiscal Year	4,810,435	5,104,045
Three Years before Current Fiscal Year	3,871,740	3,678,223
Four Years before Current Fiscal Year	2,936,646	2,400,331
Prior	4,261,980	3,686,038
Revolving Loans	11,460,495	9,612,862
Revolving Loans Converted to Term Loans	191,523	237,041
Total	48,202,430	41,693,781
Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	12,365,799	10,487,630
One Year before Current Fiscal Year	8,084,723	6,171,008
Two Years before Current Fiscal Year	4,590,045	5,019,097
Three Years before Current Fiscal Year	3,791,578	3,553,784
Four Years before Current Fiscal Year	2,786,218	2,329,521
Prior	4,158,181	3,569,404
Revolving Loans	11,359,948	9,497,636
Revolving Loans Converted to Term Loans	169,958	232,645
Total	47,306,450	40,860,725
Pass [Member] | Federal Housing Administration Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Nonaccrual loans guaranteed by the FHA	818	1,600
Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	80,235	159,448
One Year before Current Fiscal Year	96,150	120,557
Two Years before Current Fiscal Year	208,970	82,632
Three Years before Current Fiscal Year	76,486	119,845
Four Years before Current Fiscal Year	142,072	48,919
Prior	76,117	94,146
Revolving Loans	99,447	115,174
Revolving Loans Converted to Term Loans	17,795	708
Total	797,272	741,429
Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	18,863	33,806
One Year before Current Fiscal Year	23,841	2,792
Two Years before Current Fiscal Year	11,420	2,316
Three Years before Current Fiscal Year	3,676	4,594
Four Years before Current Fiscal Year	8,356	21,891
Prior	27,682	22,488
Revolving Loans	1,100	52
Revolving Loans Converted to Term Loans	3,770	3,688
Total	98,708	91,627
HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Amount converted to loans	0	54,100	$ 145,000
Commercial Lending
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	8,898,251	8,046,445
One Year before Current Fiscal Year	5,745,996	4,177,452
Two Years before Current Fiscal Year	3,020,575	3,721,211
Three Years before Current Fiscal Year	2,761,676	2,590,956
Four Years before Current Fiscal Year	2,111,867	1,622,234
Prior	2,719,920	2,486,373
Revolving Loans	9,462,895	7,647,844
Revolving Loans Converted to Term Loans	59,273	35,231
Total	34,780,453	30,327,746
Amount converted to loans	26,200	6,500	$ 23,900
Commercial Lending | C&I
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	2,922,766	4,026,214
One Year before Current Fiscal Year	2,092,308	1,253,234
Two Years before Current Fiscal Year	682,520	701,797
Three Years before Current Fiscal Year	426,477	239,265
Four Years before Current Fiscal Year	170,234	156,829
Prior	120,853	245,775
Revolving Loans	9,275,389	7,498,652
Revolving Loans Converted to Term Loans	20,548	28,842
Total	15,711,095	14,150,608
Commercial Lending | C&I | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	2,831,834	3,911,722
One Year before Current Fiscal Year	2,053,215	1,133,085
Two Years before Current Fiscal Year	623,026	629,007
Three Years before Current Fiscal Year	392,013	187,195
Four Years before Current Fiscal Year	143,970	132,392
Prior	97,605	225,326
Revolving Loans	9,177,401	7,383,485
Revolving Loans Converted to Term Loans	20,548	28,842
Total	15,339,612	13,631,054
Commercial Lending | C&I | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	72,210	85,036
One Year before Current Fiscal Year	34,296	117,357
Two Years before Current Fiscal Year	48,761	72,277
Three Years before Current Fiscal Year	34,221	51,553
Four Years before Current Fiscal Year	20,646	15,136
Prior	12,933	4,005
Revolving Loans	97,988	115,167
Revolving Loans Converted to Term Loans	0	0
Total	321,055	460,531
Commercial Lending | C&I | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	18,722	29,456
One Year before Current Fiscal Year	4,797	2,792
Two Years before Current Fiscal Year	10,733	513
Three Years before Current Fiscal Year	243	517
Four Years before Current Fiscal Year	5,618	9,301
Prior	10,315	16,444
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	50,428	59,023
Commercial Lending | CRE
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	4,182,298	2,867,598
One Year before Current Fiscal Year	2,484,251	2,093,703
Two Years before Current Fiscal Year	1,664,574	2,239,696
Three Years before Current Fiscal Year	1,811,774	1,884,558
Four Years before Current Fiscal Year	1,562,842	1,150,285
Prior	1,946,298	1,784,150
Revolving Loans	167,108	128,668
Revolving Loans Converted to Term Loans	38,725	6,389
Total	13,857,870	12,155,047
Commercial Lending | CRE | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	4,178,780	2,792,193
One Year before Current Fiscal Year	2,404,634	2,090,503
Two Years before Current Fiscal Year	1,505,150	2,230,520
Three Years before Current Fiscal Year	1,771,679	1,863,481
Four Years before Current Fiscal Year	1,471,710	1,120,682
Prior	1,909,925	1,727,862
Revolving Loans	165,653	128,668
Revolving Loans Converted to Term Loans	22,009	6,389
Total	13,429,540	11,960,298
Commercial Lending | CRE | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,518	71,055
One Year before Current Fiscal Year	60,573	3,200
Two Years before Current Fiscal Year	159,424	9,176
Three Years before Current Fiscal Year	40,095	21,077
Four Years before Current Fiscal Year	91,132	24,851
Prior	32,173	55,892
Revolving Loans	1,455	0
Revolving Loans Converted to Term Loans	16,716	0
Total	405,086	185,251
Commercial Lending | CRE | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	4,350
One Year before Current Fiscal Year	19,044	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	4,752
Prior	4,200	396
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	23,244	9,498
Commercial Lending | Real estate loan | Multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,500,289	1,026,295
One Year before Current Fiscal Year	892,598	726,772
Two Years before Current Fiscal Year	641,677	689,174
Three Years before Current Fiscal Year	520,321	441,663
Four Years before Current Fiscal Year	354,320	315,120
Prior	652,538	456,057
Revolving Loans	11,325	20,524
Revolving Loans Converted to Term Loans	0	0
Total	4,573,068	3,675,605
Commercial Lending | Real estate loan | Multifamily | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,500,289	1,026,295
One Year before Current Fiscal Year	892,598	726,772
Two Years before Current Fiscal Year	641,677	688,453
Three Years before Current Fiscal Year	519,614	419,319
Four Years before Current Fiscal Year	350,044	308,087
Prior	625,293	424,947
Revolving Loans	11,325	20,524
Revolving Loans Converted to Term Loans	0	0
Total	4,540,840	3,614,397
Commercial Lending | Real estate loan | Multifamily | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	721
Three Years before Current Fiscal Year	707	22,344
Four Years before Current Fiscal Year	4,276	7,033
Prior	27,076	30,666
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	32,059	60,764
Commercial Lending | Real estate loan | Multifamily | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	169	444
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	169	444
Commercial Lending | Construction and land
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	292,898	126,338
One Year before Current Fiscal Year	276,839	103,743
Two Years before Current Fiscal Year	31,804	90,544
Three Years before Current Fiscal Year	3,104	25,470
Four Years before Current Fiscal Year	24,471	0
Prior	231	391
Revolving Loans	9,073	0
Revolving Loans Converted to Term Loans	0	0
Total	638,420	346,486
Commercial Lending | Construction and land | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	288,394	122,983
One Year before Current Fiscal Year	276,839	103,743
Two Years before Current Fiscal Year	31,804	90,544
Three Years before Current Fiscal Year	3,104	3,412
Four Years before Current Fiscal Year	2,805	0
Prior	231	391
Revolving Loans	9,073	0
Revolving Loans Converted to Term Loans	0	0
Total	612,250	321,073
Commercial Lending | Construction and land | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	4,504	3,355
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	22,058
Four Years before Current Fiscal Year	21,666	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	26,170	25,413
Commercial Lending | Construction and land | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Lending | Total CRE
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	5,975,485	4,020,231
One Year before Current Fiscal Year	3,653,688	2,924,218
Two Years before Current Fiscal Year	2,338,055	3,019,414
Three Years before Current Fiscal Year	2,335,199	2,351,691
Four Years before Current Fiscal Year	1,941,633	1,465,405
Prior	2,599,067	2,240,598
Revolving Loans	187,506	149,192
Revolving Loans Converted to Term Loans	38,725	6,389
Total	19,069,358	16,177,138
Consumer Lending
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,566,646	2,634,439
One Year before Current Fiscal Year	2,458,718	2,116,905
Two Years before Current Fiscal Year	1,789,860	1,382,834
Three Years before Current Fiscal Year	1,110,064	1,087,267
Four Years before Current Fiscal Year	824,779	778,097
Prior	1,542,060	1,199,665
Revolving Loans	1,997,600	1,965,018
Revolving Loans Converted to Term Loans	132,250	201,810
Total	13,421,977	11,366,035
Consumer Lending | Real estate loan | Single-family
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,549,035	2,616,958
One Year before Current Fiscal Year	2,454,992	2,108,370
Two Years before Current Fiscal Year	1,776,685	1,378,138
Three Years before Current Fiscal Year	1,106,630	1,085,732
Four Years before Current Fiscal Year	823,237	769,545
Prior	1,512,448	1,134,959
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	11,223,027	9,093,702
Consumer Lending | Real estate loan | Single-family | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,548,894	2,616,958
One Year before Current Fiscal Year	2,453,717	2,108,370
Two Years before Current Fiscal Year	1,775,696	1,375,929
Three Years before Current Fiscal Year	1,101,965	1,079,030
Four Years before Current Fiscal Year	817,164	763,351
Prior	1,500,359	1,127,516
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	11,197,795	9,071,154
Consumer Lending | Real estate loan | Single-family | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	1,275	0
Two Years before Current Fiscal Year	785	458
Three Years before Current Fiscal Year	1,463	2,813
Four Years before Current Fiscal Year	4,352	1,899
Prior	3,935	3,212
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	11,810	8,382
Consumer Lending | Real estate loan | Single-family | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	141	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	204	1,751
Three Years before Current Fiscal Year	3,202	3,889
Four Years before Current Fiscal Year	1,721	4,295
Prior	8,154	4,231
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	13,422	14,166
Consumer Lending | HELOCs
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	520	648
One Year before Current Fiscal Year	3,589	3,277
Two Years before Current Fiscal Year	7,819	4,696
Three Years before Current Fiscal Year	3,434	1,535
Four Years before Current Fiscal Year	1,542	6,811
Prior	13,804	12,559
Revolving Loans	1,959,697	1,913,485
Revolving Loans Converted to Term Loans	132,250	201,810
Total	2,122,655	2,144,821
Consumer Lending | HELOCs | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	520	648
One Year before Current Fiscal Year	3,583	3,277
Two Years before Current Fiscal Year	7,336	4,644
Three Years before Current Fiscal Year	3,203	1,347
Four Years before Current Fiscal Year	525	3,268
Prior	8,960	11,215
Revolving Loans	1,958,692	1,913,478
Revolving Loans Converted to Term Loans	127,401	197,414
Total	2,110,220	2,135,291
Consumer Lending | HELOCs | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	6	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	0	371
Revolving Loans	4	7
Revolving Loans Converted to Term Loans	1,079	708
Total	1,089	1,086
Consumer Lending | HELOCs | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	483	52
Three Years before Current Fiscal Year	231	188
Four Years before Current Fiscal Year	1,017	3,543
Prior	4,844	973
Revolving Loans	1,001	0
Revolving Loans Converted to Term Loans	3,770	3,688
Total	11,346	8,444
Consumer Lending | Total residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,549,555	2,617,606
One Year before Current Fiscal Year	2,458,581	2,111,647
Two Years before Current Fiscal Year	1,784,504	1,382,834
Three Years before Current Fiscal Year	1,110,064	1,087,267
Four Years before Current Fiscal Year	824,779	776,356
Prior	1,526,252	1,147,518
Revolving Loans	1,959,697	1,913,485
Revolving Loans Converted to Term Loans	132,250	201,810
Total	13,345,682	11,238,523
Consumer Lending | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	17,091	16,833
One Year before Current Fiscal Year	137	5,258
Two Years before Current Fiscal Year	5,356	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	1,741
Prior	15,808	52,147
Revolving Loans	37,903	51,533
Revolving Loans Converted to Term Loans	0	0
Total	76,295	127,512
Consumer Lending | Other consumer | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	17,088	16,831
One Year before Current Fiscal Year	137	5,258
Two Years before Current Fiscal Year	5,356	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	1,741
Prior	15,808	52,147
Revolving Loans	37,804	51,481
Revolving Loans Converted to Term Loans	0	0
Total	76,193	127,458
Consumer Lending | Other consumer | Criticized (accrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3	2
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	3	2
Consumer Lending | Other consumer | Criticized (nonaccrual)
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
One Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving Loans	99	52
Revolving Loans Converted to Term Loans	0	0
Total	$ 99	$ 52