Loans Receivable and Allowance for Credit Losses - Aging Analysis on Loans Held-for-Investment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current, Past Due or Nonaccrual Loans
Total	$ 51,992,504	$ 52,210,782
Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	51,736,401	51,984,909
Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	107,924	122,999
Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	71,501	88,791
Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	36,423	34,208
Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	148,179	102,874
Commercial lending
Current, Past Due or Nonaccrual Loans
Total	36,644,030	37,045,191
Commercial lending | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	36,504,760	36,927,223
Commercial lending | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	38,420	53,014
Commercial lending | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	23,653	44,117
Commercial lending | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	14,767	8,897
Commercial lending | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	100,850	64,954
Commercial lending | Commercial and industrial (“C&I”)
Current, Past Due or Nonaccrual Loans
Total	16,350,191	16,581,079
Commercial lending | Commercial and industrial (“C&I”) | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	16,281,903	16,508,394
Commercial lending | Commercial and industrial (“C&I”) | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	19,326	35,649
Commercial lending | Commercial and industrial (“C&I”) | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	4,559	28,550
Commercial lending | Commercial and industrial (“C&I”) | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	14,767	7,099
Commercial lending | Commercial and industrial (“C&I”) | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	48,962	37,036
Commercial lending | CRE
Current, Past Due or Nonaccrual Loans
Total	14,609,655	14,777,081
Commercial lending | CRE | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	14,555,923	14,750,315
Commercial lending | CRE | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	18,726	3,517
Commercial lending | CRE | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	18,726	1,719
Commercial lending | CRE | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	0	1,798
Commercial lending | CRE | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	35,006	23,249
Commercial lending | Real estate loan | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	5,010,245	5,023,163
Commercial lending | Real estate loan | Current Accruing Loans | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	5,005,231	5,017,897
Commercial lending | Real estate loan | Total Accruing Past Due Loans | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	368	597
Commercial lending | Real estate loan | Accruing Loans 30-59 Days Past Due | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	368	597
Commercial lending | Real estate loan | Accruing Loans 60-89 Days Past Due | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	0	0
Commercial lending | Real estate loan | Nonperforming Financial Instruments | Multifamily residential
Current, Past Due or Nonaccrual Loans
Total	4,646	4,669
Commercial lending | Construction and land
Current, Past Due or Nonaccrual Loans
Total	673,939	663,868
Commercial lending | Construction and land | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	661,703	650,617
Commercial lending | Construction and land | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	0	13,251
Commercial lending | Construction and land | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	0	13,251
Commercial lending | Construction and land | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	0	0
Commercial lending | Construction and land | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	12,236	0
Commercial lending | Total CRE
Current, Past Due or Nonaccrual Loans
Total	20,293,839	20,464,112
Commercial lending | Total CRE | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	20,222,857	20,418,829
Commercial lending | Total CRE | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	19,094	17,365
Commercial lending | Total CRE | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	19,094	15,567
Commercial lending | Total CRE | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	0	1,798
Commercial lending | Total CRE | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	51,888	27,918
Consumer lending
Current, Past Due or Nonaccrual Loans
Total	15,348,474	15,165,591
Consumer lending | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	15,231,641	15,057,686
Consumer lending | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	69,504	69,985
Consumer lending | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	47,848	44,674
Consumer lending | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	21,656	25,311
Consumer lending | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	47,329	37,920
Consumer lending | Real estate loan | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	13,563,738	13,383,060
Consumer lending | Real estate loan | Current Accruing Loans | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	13,478,789	13,313,455
Consumer lending | Real estate loan | Total Accruing Past Due Loans | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	49,280	45,228
Consumer lending | Real estate loan | Accruing Loans 30-59 Days Past Due | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	33,911	29,285
Consumer lending | Real estate loan | Accruing Loans 60-89 Days Past Due | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	15,369	15,943
Consumer lending | Real estate loan | Nonperforming Financial Instruments | Single-family residential
Current, Past Due or Nonaccrual Loans
Total	35,669	24,377
Consumer lending | HELOCs
Current, Past Due or Nonaccrual Loans
Total	1,731,233	1,722,204
Consumer lending | HELOCs | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	1,699,628	1,687,301
Consumer lending | HELOCs | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	20,107	21,492
Consumer lending | HELOCs | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	13,877	12,266
Consumer lending | HELOCs | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	6,230	9,226
Consumer lending | HELOCs | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	11,498	13,411
Consumer lending | Total residential mortgage
Current, Past Due or Nonaccrual Loans
Total	15,294,971	15,105,264
Consumer lending | Total residential mortgage | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	15,178,417	15,000,756
Consumer lending | Total residential mortgage | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	69,387	66,720
Consumer lending | Total residential mortgage | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	47,788	41,551
Consumer lending | Total residential mortgage | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	21,599	25,169
Consumer lending | Total residential mortgage | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	47,167	37,788
Consumer lending | Other consumer
Current, Past Due or Nonaccrual Loans
Total	53,503	60,327
Consumer lending | Other consumer | Current Accruing Loans
Current, Past Due or Nonaccrual Loans
Total	53,224	56,930
Consumer lending | Other consumer | Total Accruing Past Due Loans
Current, Past Due or Nonaccrual Loans
Total	117	3,265
Consumer lending | Other consumer | Accruing Loans 30-59 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	60	3,123
Consumer lending | Other consumer | Accruing Loans 60-89 Days Past Due
Current, Past Due or Nonaccrual Loans
Total	57	142
Consumer lending | Other consumer | Nonperforming Financial Instruments
Current, Past Due or Nonaccrual Loans
Total	$ 162	$ 132