Loans and Leases Receivable and Allowance for Credit Losses on Loans and Leases - Schedule of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 135,311	$ 130,924	$ 130,924
Charge-offs	(22,827)	(21,114)	(95,066)
Recoveries	4,859	2,463
Provision (benefit) for credit losses on loans and leases	15,953	18,008
Ending balance	133,296	130,281	135,311
Commercial and industrial, including specialized lending
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	23,503	17,582	17,582
Charge-offs	(5,396)	(160)
Recoveries	1,724	231
Provision (benefit) for credit losses on loans and leases	3,172	2,397
Ending balance	23,003	20,050	23,503
Multifamily
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	16,343	14,541	14,541
Charge-offs	(473)	0
Recoveries	0	0
Provision (benefit) for credit losses on loans and leases	2,437	543
Ending balance	18,307	15,084	16,343
Commercial real estate owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9,882	6,454	6,454
Charge-offs	(22)	0
Recoveries	0	0
Provision (benefit) for credit losses on loans and leases	341	2,018
Ending balance	10,201	8,472	9,882
Commercial real estate non-owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	16,859	11,219	11,219
Charge-offs	0	(4,239)
Recoveries	0	5
Provision (benefit) for credit losses on loans and leases	1,461	4,047
Ending balance	18,320	11,032	16,859
Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,482	1,913	1,913
Charge-offs	0	0
Recoveries	0	116
Provision (benefit) for credit losses on loans and leases	384	307
Ending balance	1,866	2,336	1,482
Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	6,586	6,094	6,094
Charge-offs	(19)	0
Recoveries	1	2
Provision (benefit) for credit losses on loans and leases	139	757
Ending balance	6,707	6,853	6,586
Manufactured housing
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,239	4,430	4,430
Charge-offs	0	0
Recoveries	0	0
Provision (benefit) for credit losses on loans and leases	(79)	(91)
Ending balance	4,160	4,339	4,239
Installment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	56,417	68,691	68,691
Charge-offs	(16,917)	(16,715)
Recoveries	3,134	2,109
Provision (benefit) for credit losses on loans and leases	8,098	8,030
Ending balance	$ 50,732	$ 62,115	$ 56,417

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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