Loans Receivable and Allowance for Credit Losses - Schedule of Loans Held-for-Investment by Loan Portfolio Segments, Internal Risk Ratings, Gross Write-Offs and Vintage Year (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	$ 2,263,064		$ 9,719,398
Year 2	9,433,254		5,653,616
Year 3	5,264,101		6,135,011
Year 4	5,846,928		8,045,731
Year 5	7,789,206		4,806,776
Prior	13,110,005		8,966,065
Revolving Loans	14,196,018		13,355,432
Revolving Loans Converted to Term Loans	198,173		196,143
Total	58,100,749		56,878,172
Gross write-offs Total	20,779	$ 16,983
Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	2,263,029		9,671,422
Year 2	9,380,301		5,570,406
Year 3	5,179,770		5,975,946
Year 4	5,661,000		7,772,190
Year 5	7,513,415		4,649,165
Prior	12,742,025		8,718,176
Revolving Loans	13,938,270		13,189,841
Revolving Loans Converted to Term Loans	193,323		189,877
Total	56,871,133		55,737,023
Pass | Federal Housing Administration Loan
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Nonaccrual loans	1,000		1,000
Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	35		35,883
Year 2	37,924		68,676
Year 3	74,070		124,210
Year 4	144,760		238,322
Year 5	250,234		132,904
Prior	285,737		209,377
Revolving Loans	256,772		165,410
Revolving Loans Converted to Term Loans	326		1,654
Total	1,049,858		976,436
Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		12,093
Year 2	15,029		14,534
Year 3	10,261		34,855
Year 4	41,168		35,219
Year 5	25,557		24,707
Prior	82,243		38,512
Revolving Loans	976		181
Revolving Loans Converted to Term Loans	4,524		4,612
Total	179,758		164,713
Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	7		11,549
Gross write-offs year 2	1,346		1,213
Gross write-offs year 3	109		28,752
Gross write-offs year 4	8,197		4,803
Gross write-offs year 5	4,609		1,082
Gross write-offs year Prior	3,281		18,304
Gross write-offs year Revolving Loans	10		24
Gross write-offs Revolving Loans Converted to Term Loans	0		6
Gross write-offs Total	17,559		65,733
Commercial Lending
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	1,504,867		6,807,946
Year 2	6,650,294		3,806,449
Year 3	3,554,893		3,771,470
Year 4	3,593,543		5,214,350
Year 5	5,027,582		2,931,930
Prior	8,134,875		5,678,998
Revolving Loans	12,391,613		11,582,085
Revolving Loans Converted to Term Loans	125,589		119,300
Total	40,983,256		39,912,528
Commercial Lending | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	0		11,549
Gross write-offs year 2	1,343		1,199
Gross write-offs year 3	89		28,752
Gross write-offs year 4	8,193		4,803
Gross write-offs year 5	4,601		1,082
Gross write-offs year Prior	3,202		18,304
Gross write-offs year Revolving Loans	10		24
Gross write-offs Revolving Loans Converted to Term Loans	0		0
Gross write-offs Total	17,438		65,713
Commercial Lending | C&I
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	665,684		3,016,862
Year 2	2,909,650		1,757,317
Year 3	1,527,859		908,739
Year 4	862,413		631,663
Year 5	530,149		484,751
Prior	699,420		316,190
Revolving Loans	12,286,168		11,467,265
Revolving Loans Converted to Term Loans	69,610		67,968
Total	19,550,953		18,650,755
Gross write-offs Total	18,385	988
Commercial Lending | C&I | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	665,659		3,013,368
Year 2	2,906,360		1,717,361
Year 3	1,485,504		880,267
Year 4	812,869		536,461
Year 5	444,075		391,413
Prior	609,918		302,893
Revolving Loans	12,030,255		11,308,551
Revolving Loans Converted to Term Loans	69,610		67,968
Total	19,024,250		18,218,282
Commercial Lending | C&I | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	25		572
Year 2	400		35,223
Year 3	38,075		1,662
Year 4	34,555		93,562
Year 5	85,971		83,813
Prior	50,822		6,771
Revolving Loans	255,792		158,626
Revolving Loans Converted to Term Loans	0		0
Total	465,640		380,229
Commercial Lending | C&I | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		2,922
Year 2	2,890		4,733
Year 3	4,280		26,810
Year 4	14,989		1,640
Year 5	103		9,525
Prior	38,680		6,526
Revolving Loans	121		88
Revolving Loans Converted to Term Loans	0		0
Total	61,063		52,244
Commercial Lending | C&I | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	0		2,617
Gross write-offs year 2	38		1,199
Gross write-offs year 3	89		28,752
Gross write-offs year 4	8,193		4,643
Gross write-offs year 5	4,601		1,063
Gross write-offs year Prior	3,202		3,170
Gross write-offs year Revolving Loans	10		24
Gross write-offs Revolving Loans Converted to Term Loans	0		0
Gross write-offs Total	16,133		41,468
Commercial Lending | CRE
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	553,283		2,649,381
Year 2	2,630,046		1,592,227
Year 3	1,577,714		2,136,467
Year 4	2,065,516		3,329,820
Year 5	3,255,535		1,769,826
Prior	5,284,550		3,803,143
Revolving Loans	72,238		78,712
Revolving Loans Converted to Term Loans	52,175		47,512
Total	15,491,057		15,407,088
Gross write-offs Total	1,305	13,937
Commercial Lending | CRE | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	553,283		2,615,789
Year 2	2,597,867		1,562,420
Year 3	1,546,632		2,015,433
Year 4	1,943,710		3,188,363
Year 5	3,100,174		1,708,927
Prior	5,050,710		3,607,918
Revolving Loans	72,238		78,712
Revolving Loans Converted to Term Loans	52,175		47,512
Total	14,916,789		14,825,074
Commercial Lending | CRE | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		30,275
Year 2	30,166		29,807
Year 3	31,082		116,862
Year 4	103,021		134,018
Year 5	155,361		48,569
Prior	218,143		183,937
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	537,773		543,468
Commercial Lending | CRE | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		3,317
Year 2	2,013		0
Year 3	0		4,172
Year 4	18,785		7,439
Year 5	0		12,330
Prior	15,697		11,288
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	36,495		38,546
Commercial Lending | CRE | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	0		8,932
Gross write-offs year 2	1,305		0
Gross write-offs year 3	0		0
Gross write-offs year 4	0		160
Gross write-offs year 5	0		19
Gross write-offs year Prior	0		15,126
Gross write-offs year Revolving Loans	0		0
Gross write-offs Revolving Loans Converted to Term Loans	0		0
Gross write-offs Total	1,305		24,237
Commercial Lending | Multifamily residential
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	229,288		895,323
Year 2	840,553		338,209
Year 3	326,725		478,782
Year 4	429,290		1,143,868
Year 5	1,137,367		663,916
Prior	2,134,118		1,556,203
Revolving Loans	28,102		32,207
Revolving Loans Converted to Term Loans	3,804		3,820
Total	5,129,247		5,112,328
Gross write-offs Total	0	4
Commercial Lending | Multifamily residential | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	229,288		895,323
Year 2	840,553		338,209
Year 3	326,725		478,782
Year 4	429,290		1,138,693
Year 5	1,132,216		663,916
Prior	2,125,158		1,547,124
Revolving Loans	28,102		32,207
Revolving Loans Converted to Term Loans	3,804		3,820
Total	5,115,136		5,098,074
Commercial Lending | Multifamily residential | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		0
Year 2	0		0
Year 3	0		0
Year 4	0		5,175
Year 5	5,151		0
Prior	8,685		8,787
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	13,836		13,962
Commercial Lending | Multifamily residential | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		0
Year 2	0		0
Year 3	0		0
Year 4	0		0
Year 5	0		0
Prior	275		292
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	275		292
Commercial Lending | Multifamily residential | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1			0
Gross write-offs year 2			0
Gross write-offs year 3			0
Gross write-offs year 4			0
Gross write-offs year 5			0
Gross write-offs year Prior			8
Gross write-offs year Revolving Loans			0
Gross write-offs Revolving Loans Converted to Term Loans			0
Gross write-offs Total			8
Commercial Lending | Construction and land
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	56,612		246,380
Year 2	270,045		118,696
Year 3	122,595		247,482
Year 4	236,324		108,999
Year 5	104,531		13,437
Prior	16,787		3,462
Revolving Loans	5,105		3,901
Revolving Loans Converted to Term Loans	0		0
Total	811,999		742,357
Gross write-offs Total	893	1,996
Commercial Lending | Construction and land | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	56,612		246,380
Year 2	270,045		109,799
Year 3	122,595		247,482
Year 4	236,324		90,086
Year 5	85,197		13,437
Prior	16,787		3,462
Revolving Loans	5,105		3,901
Revolving Loans Converted to Term Loans	0		0
Total	792,665		714,547
Commercial Lending | Construction and land | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		0
Year 2	0		8,897
Year 3	0		0
Year 4	0		18,913
Year 5	19,334		0
Prior	0		0
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	19,334		27,810
Commercial Lending | Total CRE
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	839,183		3,791,084
Year 2	3,740,644		2,049,132
Year 3	2,027,034		2,862,731
Year 4	2,731,130		4,582,687
Year 5	4,497,433		2,447,179
Prior	7,435,455		5,362,808
Revolving Loans	105,445		114,820
Revolving Loans Converted to Term Loans	55,979		51,332
Total	21,432,303		21,261,773
Gross write-offs year 1	0
Gross write-offs year 2	1,305
Gross write-offs year 3	0
Gross write-offs year 4	0
Gross write-offs year 5	0
Gross write-offs year Prior	0
Gross write-offs year Revolving Loans	0
Gross write-offs Revolving Loans Converted to Term Loans	0
Gross write-offs Total	1,305
Commercial Lending | Total CRE | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1			8,932
Gross write-offs year 2			0
Gross write-offs year 3			0
Gross write-offs year 4			160
Gross write-offs year 5			19
Gross write-offs year Prior			15,134
Gross write-offs year Revolving Loans			0
Gross write-offs Revolving Loans Converted to Term Loans			0
Gross write-offs Total			24,245
Consumer Lending
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	758,197		2,911,452
Year 2	2,782,960		1,847,167
Year 3	1,709,208		2,363,541
Year 4	2,253,385		2,831,381
Year 5	2,761,624		1,874,846
Prior	4,975,130		3,287,067
Revolving Loans	1,804,405		1,773,347
Revolving Loans Converted to Term Loans	72,584		76,843
Total	17,117,493		16,965,644
Consumer Lending | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	7		0
Gross write-offs year 2	3		14
Gross write-offs year 3	20		0
Gross write-offs year 4	4		0
Gross write-offs year 5	8		0
Gross write-offs year Prior	79		0
Gross write-offs year Revolving Loans	0		0
Gross write-offs Revolving Loans Converted to Term Loans	0		6
Gross write-offs Total	121		20
Consumer Lending | Single-family residential (“SFR”)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	756,418		2,869,487
Year 2	2,743,207		1,842,358
Year 3	1,706,405		2,358,276
Year 4	2,245,312		2,818,738
Year 5	2,744,054		1,861,965
Prior	4,924,313		3,251,725
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	15,119,709		15,002,549
Gross write-offs Total	121	9
Consumer Lending | Single-family residential (“SFR”) | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	756,418		2,861,764
Year 2	2,727,809		1,837,821
Year 3	1,696,060		2,349,242
Year 4	2,233,611		2,808,694
Year 5	2,737,115		1,860,110
Prior	4,906,622		3,228,996
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	15,057,635		14,946,627
Consumer Lending | Single-family residential (“SFR”) | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		3,157
Year 2	6,395		3,646
Year 3	4,497		5,589
Year 4	6,832		5,427
Year 5	3,751		235
Prior	6,995		9,356
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	28,470		27,410
Consumer Lending | Single-family residential (“SFR”) | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		4,566
Year 2	9,003		891
Year 3	5,848		3,445
Year 4	4,869		4,617
Year 5	3,188		1,620
Prior	10,696		13,373
Revolving Loans	0		0
Revolving Loans Converted to Term Loans	0		0
Total	33,604		28,512
Consumer Lending | Single-family residential (“SFR”) | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	7		0
Gross write-offs year 2	3		14
Gross write-offs year 3	20		0
Gross write-offs year 4	4		0
Gross write-offs year 5	8		0
Gross write-offs year Prior	79		0
Gross write-offs year Revolving Loans	0		0
Gross write-offs Revolving Loans Converted to Term Loans	0		0
Gross write-offs Total	121		14
Consumer Lending | Home equity lines of credit (“HELOCs”)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	400		16,819
Year 2	15,272		4,809
Year 3	2,803		5,216
Year 4	8,073		8,008
Year 5	12,919		12,752
Prior	45,123		29,772
Revolving Loans	1,788,693		1,757,678
Revolving Loans Converted to Term Loans	72,584		76,843
Total	1,945,867		1,911,897
Gross write-offs Total	0	0
Consumer Lending | Home equity lines of credit (“HELOCs”) | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	400		13,652
Year 2	13,186		4,796
Year 3	2,254		4,740
Year 4	5,196		5,258
Year 5	9,987		11,233
Prior	27,136		22,213
Revolving Loans	1,786,887		1,750,894
Revolving Loans Converted to Term Loans	67,734		70,577
Total	1,912,780		1,883,363
Consumer Lending | Home equity lines of credit (“HELOCs”) | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		1,879
Year 2	963		0
Year 3	416		97
Year 4	352		140
Year 5	0		287
Prior	1,092		526
Revolving Loans	980		6,784
Revolving Loans Converted to Term Loans	326		1,654
Total	4,129		11,367
Consumer Lending | Home equity lines of credit (“HELOCs”) | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		1,288
Year 2	1,123		13
Year 3	133		379
Year 4	2,525		2,610
Year 5	2,932		1,232
Prior	16,895		7,033
Revolving Loans	826		0
Revolving Loans Converted to Term Loans	4,524		4,612
Total	28,958		17,167
Consumer Lending | Home equity lines of credit (“HELOCs”) | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1			0
Gross write-offs year 2			0
Gross write-offs year 3			0
Gross write-offs year 4			0
Gross write-offs year 5			0
Gross write-offs year Prior			0
Gross write-offs year Revolving Loans			0
Gross write-offs Revolving Loans Converted to Term Loans			6
Gross write-offs Total			6
Consumer Lending | Total residential mortgage
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	756,818		2,886,306
Year 2	2,758,479		1,847,167
Year 3	1,709,208		2,363,492
Year 4	2,253,385		2,826,746
Year 5	2,756,973		1,874,717
Prior	4,969,436		3,281,497
Revolving Loans	1,788,693		1,757,678
Revolving Loans Converted to Term Loans	72,584		76,843
Total	17,065,576		16,914,446
Consumer Lending | Total residential mortgage | Gross write-offs
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Gross write-offs year 1	7		0
Gross write-offs year 2	3		14
Gross write-offs year 3	20		0
Gross write-offs year 4	4		0
Gross write-offs year 5	8		0
Gross write-offs year Prior	79		0
Gross write-offs year Revolving Loans	0		0
Gross write-offs Revolving Loans Converted to Term Loans	0		6
Gross write-offs Total	121		20
Consumer Lending | Other consumer
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	1,379		25,146
Year 2	24,481		0
Year 3	0		49
Year 4	0		4,635
Year 5	4,651		129
Prior	5,694		5,570
Revolving Loans	15,712		15,669
Revolving Loans Converted to Term Loans	0		0
Total	51,917		51,198
Gross write-offs Total	75	$ 49
Consumer Lending | Other consumer | Pass
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	1,369		25,146
Year 2	24,481		0
Year 3	0		0
Year 4	0		4,635
Year 5	4,651		129
Prior	5,694		5,570
Revolving Loans	15,683		15,576
Revolving Loans Converted to Term Loans	0		0
Total	51,878		51,056
Consumer Lending | Other consumer | Criticized (accrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	10
Year 2	0
Year 3	0
Year 4	0
Year 5	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	10
Consumer Lending | Other consumer | Criticized (nonaccrual)
Financing Receivable, Vintage Year/Credit Quality Indicator [Line Items]
Year 1	0		0
Year 2	0		0
Year 3	0		49
Year 4	0		0
Year 5	0		0
Prior	0		0
Revolving Loans	29		93
Revolving Loans Converted to Term Loans	0		0
Total	$ 29		$ 142