Loans Receivable and Allowance for Credit Losses - Summary of Activities in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2022
Allowance for loan losses
Allowance for loan losses, start of period	$ 668,743	$ 595,645
(Reversal of) provision for credit losses on loans	24,155	18,520
Gross charge-offs	(24,684)	(2,037)
Gross recoveries	2,107	1,428
Total net (charge-offs) recoveries	(22,577)	(609)
Foreign currency translation adjustment	(41)	309
Allowance for loan losses, end of period	670,280	619,893
Commercial lending \| Commercial and industrial (“C&I”)
Allowance for loan losses
Allowance for loan losses, start of period	392,685	371,700
(Reversal of) provision for credit losses on loans	275	(678)
Gross charge-offs	(20,998)	(1,900)
Gross recoveries	1,710	1,211
Total net (charge-offs) recoveries	(19,288)	(689)
Foreign currency translation adjustment	(41)	309
Allowance for loan losses, end of period	373,631	376,325
Commercial lending \| CRE
Allowance for loan losses
Allowance for loan losses, start of period	170,592	149,864
(Reversal of) provision for credit losses on loans	18,939	4,676
Gross charge-offs	(2,398)	(6)
Gross recoveries	327	196
Total net (charge-offs) recoveries	(2,071)	190
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	187,460	155,067
Commercial lending \| Residential loan \| Multifamily residential
Allowance for loan losses
Allowance for loan losses, start of period	34,375	23,373
(Reversal of) provision for credit losses on loans	3,032	1,135
Gross charge-offs	(6)	0
Gross recoveries	17	12
Total net (charge-offs) recoveries	11	12
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	37,418	24,526
Commercial lending \| Construction and land
Allowance for loan losses
Allowance for loan losses, start of period	10,469	9,109
(Reversal of) provision for credit losses on loans	1,574	210
Gross charge-offs	(1,224)	0
Gross recoveries	0	3
Total net (charge-offs) recoveries	(1,224)	3
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	10,819	9,322
Consumer lending \| Residential loan \| Single-family residential
Allowance for loan losses
Allowance for loan losses, start of period	55,018	35,564
(Reversal of) provision for credit losses on loans	899	12,442
Gross charge-offs	0	0
Gross recoveries	5	0
Total net (charge-offs) recoveries	5	0
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	55,922	48,007
Consumer lending \| HELOCs
Allowance for loan losses
Allowance for loan losses, start of period	3,947	4,475
(Reversal of) provision for credit losses on loans	(432)	580
Gross charge-offs	0	(91)
Gross recoveries	48	6
Total net (charge-offs) recoveries	48	(85)
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	3,563	4,971
Consumer lending \| Other consumer
Allowance for loan losses
Allowance for loan losses, start of period	1,657	1,560
(Reversal of) provision for credit losses on loans	(132)	155
Gross charge-offs	(58)	(40)
Gross recoveries	0	0
Total net (charge-offs) recoveries	(58)	(40)
Foreign currency translation adjustment	0	0
Allowance for loan losses, end of period	$ 1,467	$ 1,675
Accounting Standards Update 2022-02
Allowance for loan losses
Impact of ASU 2022-02 adoption			$ 6,028
Accounting Standards Update 2022-02 \| Commercial lending \| Commercial and industrial (“C&I”)
Allowance for loan losses
Impact of ASU 2022-02 adoption			5,683
Accounting Standards Update 2022-02 \| Commercial lending \| CRE
Allowance for loan losses
Impact of ASU 2022-02 adoption			337
Accounting Standards Update 2022-02 \| Commercial lending \| Residential loan \| Multifamily residential
Allowance for loan losses
Impact of ASU 2022-02 adoption			6
Accounting Standards Update 2022-02 \| Commercial lending \| Construction and land
Allowance for loan losses
Impact of ASU 2022-02 adoption			0
Accounting Standards Update 2022-02 \| Consumer lending \| Residential loan \| Single-family residential
Allowance for loan losses
Impact of ASU 2022-02 adoption			1
Accounting Standards Update 2022-02 \| Consumer lending \| HELOCs
Allowance for loan losses
Impact of ASU 2022-02 adoption			1
Accounting Standards Update 2022-02 \| Consumer lending \| Other consumer
Allowance for loan losses
Impact of ASU 2022-02 adoption			$ 0

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

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

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