Summary of Significant Accounting Policies - Additional Information (Detail) Loans in Millions, Borrowers in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) Loans	Dec. 31, 2021 USD ($) Borrowers	Dec. 31, 2020 USD ($)
Servicing assets, fair value	$ 221,000	$ 248,000
Investments	47,012,000	74,892,000
Income tax benefits recognized	8,798,000	5,094,000
Goodwill, impairment loss	$ 0
Income tax realized on settlement, percentage	50.00%
Interest Income	$ 970,000	609,000
Loan Commitments	10,000,000	10,000,000
Deposits	7,810,000	4,418,000
Interest expense	$ 11,306,000	$ 6,563,000
Residential Loan Porfolios [Member]
Number of loan porfolios purchased | Borrowers		42.7
Commercial Loan [Member]
Number of loan porfolios purchased | Loans	56.4
Core Deposits [Member]
Core deposit intangible asset value	$ 122,000
Core deposit intangible asset useful life	4 years
Core deposit intangible asset, amortization	$ 41,000
Deposits	58,300,000	$ 36,400,000
Interest expense	273,000	273,000
Low Income Housing Tax Credit [Member]
Investments in low income housing tax credits, commitments			$ 13,600,000
Investment commitments capital call		614,000,000,000
New investments acquired	669,000
Investments	6,200,000	7,400,000
Investments, commitments remaining for future capital call	1,000,000	1,700,000
Income tax benefits recognized	208,000,000	207,000,000
Low income housing tax credits and other benefits recognized	361,000	1,400,000
Amortization expense of investment in low income housing tax credit	$ 1,200,000	$ 1,200,000
Minimum [Member]
Related party interest rate in the entity	10.00%
Furniture and Fixtures [Member] | Minimum [Member]
Estimated useful life	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Estimated useful life	5 years
Leasehold Improvements [Member] | Minimum [Member]
Estimated useful life	7 years
Leasehold Improvements [Member] | Maximum [Member]
Estimated useful life	14 years