Loans Receivable and Allowance for Credit Losses - Summary of Activities in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for loan losses
Allowance for loan losses, December 31, 2022		$ 595,645
Allowance for loan losses, balance at the beginning of the period	$ 595,645	541,579	$ 619,983
Provision for (reversal of) credit losses	113,571	74,767	(28,954)
Gross charge-offs	(54,372)	(37,920)	(66,592)
Gross recoveries	8,118	19,461	16,614
Total net (charge-offs) recoveries	(46,254)	(18,459)	(49,978)
Foreign currency translation adjustment	(247)	(2,242)	528
Allowance for loan losses, balance at the end of the period	668,743	595,645	541,579
Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		6,028
Allowance for loan losses, balance at the beginning of the period	(6,000)
Allowance for loan losses, balance at the end of the period		(6,000)
Commercial Lending \| C&I
Allowance for loan losses
Allowance for loan losses, December 31, 2022		371,700
Allowance for loan losses, balance at the beginning of the period	371,700	338,252	398,040
Provision for (reversal of) credit losses	45,319	37,604	(39,732)
Gross charge-offs	(36,573)	(18,738)	(32,490)
Gross recoveries	6,803	16,824	11,906
Total net (charge-offs) recoveries	(29,770)	(1,914)	(20,584)
Foreign currency translation adjustment	(247)	(2,242)	528
Allowance for loan losses, balance at the end of the period	392,685	371,700	338,252
Commercial Lending \| C&I \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		5,683
Commercial Lending \| CRE
Allowance for loan losses
Allowance for loan losses, December 31, 2022		149,864
Allowance for loan losses, balance at the beginning of the period	149,864	150,940	163,791
Provision for (reversal of) credit losses	27,007	8,212	14,282
Gross charge-offs	(7,048)	(10,871)	(28,430)
Gross recoveries	432	1,583	1,297
Total net (charge-offs) recoveries	(6,616)	(9,288)	(27,133)
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	170,592	149,864	150,940
Commercial Lending \| CRE \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		337
Commercial Lending \| Residential loan \| Multifamily Residential
Allowance for loan losses
Allowance for loan losses, December 31, 2022		23,373
Allowance for loan losses, balance at the beginning of the period	23,373	14,400	27,573
Provision for (reversal of) credit losses	10,454	15,651	(15,076)
Gross charge-offs	(3)	(7,237)	(130)
Gross recoveries	545	559	2,033
Total net (charge-offs) recoveries	542	(6,678)	1,903
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	34,375	23,373	14,400
Commercial Lending \| Residential loan \| Multifamily Residential \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		6
Commercial Lending \| Construction and land
Allowance for loan losses
Allowance for loan losses, December 31, 2022		9,109
Allowance for loan losses, balance at the beginning of the period	9,109	15,468	10,239
Provision for (reversal of) credit losses	11,537	(6,433)	7,576
Gross charge-offs	(10,413)	0	(2,954)
Gross recoveries	236	74	607
Total net (charge-offs) recoveries	(10,177)	74	(2,347)
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	10,469	9,109	15,468
Commercial Lending \| Construction and land \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		0
Consumer Lending \| Residential loan \| Single-Family Residential
Allowance for loan losses
Allowance for loan losses, December 31, 2022		35,564
Allowance for loan losses, balance at the beginning of the period	35,564	17,160	15,520
Provision for (reversal of) credit losses	19,384	18,867	1,965
Gross charge-offs	0	(775)	(1,046)
Gross recoveries	69	312	721
Total net (charge-offs) recoveries	69	(463)	(325)
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	55,018	35,564	17,160
Consumer Lending \| Residential loan \| Single-Family Residential \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		1
Consumer Lending \| HELOCs
Allowance for loan losses
Allowance for loan losses, December 31, 2022		4,475
Allowance for loan losses, balance at the beginning of the period	4,475	3,435	2,690
Provision for (reversal of) credit losses	(424)	1,124	745
Gross charge-offs	(138)	(193)	(45)
Gross recoveries	33	109	45
Total net (charge-offs) recoveries	(105)	(84)	0
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	3,947	4,475	3,435
Consumer Lending \| HELOCs \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		1
Consumer Lending \| Other consumer
Allowance for loan losses
Allowance for loan losses, December 31, 2022		1,560
Allowance for loan losses, balance at the beginning of the period	1,560	1,924	2,130
Provision for (reversal of) credit losses	294	(258)	1,286
Gross charge-offs	(197)	(106)	(1,497)
Gross recoveries	0	0	5
Total net (charge-offs) recoveries	(197)	(106)	(1,492)
Foreign currency translation adjustment	0	0	0
Allowance for loan losses, balance at the end of the period	$ 1,657	1,560	$ 1,924
Consumer Lending \| Other consumer \| Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption		$ 0

Financing Receivable Allowance For Credit Loss Excluding Accrued Interest Before Impact of Adoption

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- Definition

Financing Receivable Allowance For Credit Loss Excluding Accrued Interest Impact of Adoption

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

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Amount of foreign currency translation gain (loss) which decreases (increases) allowance for credit loss on financing receivable. Excludes net investment in lease.

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Amount, after recovery, of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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