Loans Receivable and Allowance for Credit Losses - Schedule Of Activity In The Allowance For Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Allowance for loan losses
Allowance for loan losses, start of period	$ 683,794	$ 635,400	$ 668,743	$ 595,645	$ 595,645
Provision for (reversal of) credit losses on loans	41,717	38,136	102,633	80,681
Gross charge-offs	(30,298)	(21,007)	(80,304)	(32,799)
Gross recoveries	935	2,861	5,229	6,507
Total net (charge-offs) recoveries	(29,363)	(18,146)	(75,075)	(26,292)
Foreign currency translation adjustment	337	133	184	(539)
Allowance for loan losses, end of period	696,485	655,523	696,485	655,523	668,743
Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				6,028	6,028
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				601,673	601,673
Commercial lending | C&I
Allowance for loan losses
Allowance for loan losses, start of period	379,984	375,333	392,685	371,700	371,700
Provision for (reversal of) credit losses on loans	26,416	13,006	44,473	17,587
Gross charge-offs	(29,260)	(7,074)	(63,392)	(16,309)
Gross recoveries	838	2,279	4,365	5,555
Total net (charge-offs) recoveries	(28,422)	(4,795)	(59,027)	(10,754)
Foreign currency translation adjustment	337	133	184	(539)
Allowance for loan losses, end of period	378,315	383,677	378,315	383,677	392,685
Commercial lending | C&I | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				5,683	5,683
Commercial lending | C&I | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				377,383	377,383
Commercial lending | CRE
Allowance for loan losses
Allowance for loan losses, start of period	194,794	168,505	170,592	149,864	149,864
Provision for (reversal of) credit losses on loans	27,123	12,952	64,542	33,313
Gross charge-offs	(734)	(3,466)	(14,235)	(5,838)
Gross recoveries	61	49	345	364
Total net (charge-offs) recoveries	(673)	(3,417)	(13,890)	(5,474)
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	221,244	178,040	221,244	178,040	170,592
Commercial lending | CRE | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				337	337
Commercial lending | CRE | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				150,201	150,201
Commercial lending | Multifamily residential
Allowance for loan losses
Allowance for loan losses, start of period	40,254	22,938	34,375	23,373	23,373
Provision for (reversal of) credit losses on loans	(8,493)	772	(2,833)	303
Gross charge-offs	0	0	(6)	0
Gross recoveries	21	452	246	480
Total net (charge-offs) recoveries	21	452	240	480
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	31,782	24,162	31,782	24,162	34,375
Commercial lending | Multifamily residential | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				6	6
Commercial lending | Multifamily residential | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				23,379	23,379
Commercial lending | Construction and land
Allowance for loan losses
Allowance for loan losses, start of period	14,322	11,325	10,469	9,109	9,109
Provision for (reversal of) credit losses on loans	(1,975)	8,302	3,828	10,507
Gross charge-offs	(145)	(10,413)	(2,289)	(10,413)
Gross recoveries	6	2	200	13
Total net (charge-offs) recoveries	(139)	(10,411)	(2,089)	(10,400)
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	12,208	9,216	12,208	9,216	10,469
Commercial lending | Construction and land | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				0	0
Commercial lending | Construction and land | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				9,109	9,109
Consumer lending | Single-family residential
Allowance for loan losses
Allowance for loan losses, start of period	49,523	51,513	55,018	35,564	35,564
Provision for (reversal of) credit losses on loans	(1,293)	3,353	(6,760)	19,296
Gross charge-offs	0	0	(35)	0
Gross recoveries	1	64	8	69
Total net (charge-offs) recoveries	1	64	(27)	69
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	48,231	54,930	48,231	54,930	55,018
Consumer lending | Single-family residential | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				1	1
Consumer lending | Single-family residential | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				35,565	35,565
Consumer lending | HELOCs
Allowance for loan losses
Allowance for loan losses, start of period	3,340	4,526	3,947	4,475	4,475
Provision for (reversal of) credit losses on loans	(128)	(705)	(792)	(569)
Gross charge-offs	(10)	(41)	(10)	(138)
Gross recoveries	8	15	65	26
Total net (charge-offs) recoveries	(2)	(26)	55	(112)
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	3,210	3,795	3,210	3,795	3,947
Consumer lending | HELOCs | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				1	1
Consumer lending | HELOCs | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				4,476	4,476
Consumer lending | Other consumer
Allowance for loan losses
Allowance for loan losses, start of period	1,577	1,260	1,657	1,560	1,560
Provision for (reversal of) credit losses on loans	67	456	175	244
Gross charge-offs	(149)	(13)	(337)	(101)
Gross recoveries	0	0	0	0
Total net (charge-offs) recoveries	(149)	(13)	(337)	(101)
Foreign currency translation adjustment	0	0	0	0
Allowance for loan losses, end of period	$ 1,495	$ 1,703	$ 1,495	1,703	1,657
Consumer lending | Other consumer | Cumulative Effect, Period Of Adoption, Adjustment | Accounting Standards Update 2022-02
Allowance for loan losses
Allowance for loan losses, start of period				0	0
Consumer lending | Other consumer | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses
Allowance for loan losses, start of period				$ 1,560	$ 1,560