Fair Value - Summary of Change in MSR Assets (Detail) - MSR Assets [Member] - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Servicing Assets At Amortized Value [Line Items]
Ending Balance, fair value	$ 16,500
Level 3 [Member]
Servicing Assets At Amortized Value [Line Items]
Beginning Balance	7,084
Additions	11,809	$ 7,539
Write-offs	(959)	(61)
Amortization	(2,462)	(391)
Impairments		(3)
Fair value adjustments	4,484	207
Ending Balance, fair value	20,953	7,291
Ending Balance, amortized cost	16,469	$ 7,084
Level 3 [Member] \| Bay Banks [Member]
Servicing Assets At Amortized Value [Line Items]
Additions	$ 997

Amount of other-than-temporary impairment (OTTI) applied to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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- Definition

Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122492-111745

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

+ Details

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- Definition

Amount of additions from purchases, assumption or transfer to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

+ Details

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- Definition

Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

+ Details

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- Definition

Amount conveyed to unrelated parties of contract to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

+ Details

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- Definition

Fair value of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

+ Details

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- Definition

Amount of increase (decrease) in the amortized amount from a decrease (increase) in the valuation allowance applied to the servicing asset for a contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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