Loans and Leases Receivable and Allowance for Credit Losses on Loans and Leases - Performance Status (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	$ 10,118,855	$ 9,018,298
Threshold period past due	30 days
Purchased-credit-impaired loans	$ 9,400	9,900
Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	2,200,000	3,300,000
Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	74,124	68,433
30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	30,316	18,374
30 to 59 Days Past Due | Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	37,800	6,300
60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	5,686	8,654
60 Days or More Past Due | Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	88,300	21,800
90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	38,122	41,405
Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	10,044,731	8,949,865
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,705,027	1,486,308
Multi-family | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	26,871	22,624
Multi-family | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	10,690	1,682
Multi-family | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	2,707
Multi-family | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	16,181	18,235
Multi-family | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,678,156	1,463,684
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	3,995,802	3,424,783
Commercial and industrial | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	8,115	8,117
Commercial and industrial | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	2,591	2,093
Commercial and industrial | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	92	95
Commercial and industrial | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	5,432	5,929
Commercial and industrial | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	3,987,687	3,416,666
Commercial real estate owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	701,893	654,922
Commercial real estate owner occupied | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	3,981	1,591
Commercial real estate owner occupied | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	2,935	287
Commercial real estate owner occupied | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Commercial real estate owner occupied | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,046	1,304
Commercial real estate owner occupied | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	697,912	653,331
Commercial real estate non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,140,311	1,121,238
Commercial real estate non-owner occupied | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,302	2,815
Commercial real estate non-owner occupied | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Commercial real estate non-owner occupied | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Commercial real estate non-owner occupied | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,302	2,815
Commercial real estate non-owner occupied | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,139,009	1,118,423
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	161,024	198,981
Construction | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Construction | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Construction | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Construction | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	0	0
Construction | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	161,024	198,981
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	466,423	334,730
Residential real estate | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	10,405	9,834
Residential real estate | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	5,151	4,655
Residential real estate | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	446	789
Residential real estate | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	4,808	4,390
Residential real estate | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	456,018	324,896
Manufactured housing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	50,669	52,861
Manufactured housing | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	5,743	8,025
Manufactured housing | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	975	2,308
Manufactured housing | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	280	768
Manufactured housing | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	4,488	4,949
Manufactured housing | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	44,926	44,836
Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	1,897,706	1,744,475
Installment | Total past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	17,707	15,427
Installment | 30 to 59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	7,974	7,349
Installment | 60 to 89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	4,868	4,295
Installment | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	4,865	3,783
Installment | Loans and leases not past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	$ 1,879,999	$ 1,729,048