Loans and Leases Held for Investment, Net of Allowance For Loan and Lease Losses - Schedule of Components of Portfolio Segment by Class of Financing Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	$ 2,899,126	$ 0
Allowance for loan and lease losses	(144,389)	0
Loans and leases held for investment, net	2,754,737	0
Loans pledged as collateral under the FRB discount window	$ 149,200
Allowance ratios	5.00%
Allowance for loan and lease losses to commercial loans and leases held for investment, excluding PPP loans, percent	5.50%
Consumer Portfolio Segment
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	$ 2,021,916
Allowance for loan and lease losses	(128,812)	0
Loans and leases held for investment, net	$ 1,893,104
Allowance ratios	6.40%
Consumer Portfolio Segment \| Unsecured personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	$ 1,804,578
Consumer Portfolio Segment \| Residential mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	151,362
Consumer Portfolio Segment \| Secured consumer
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	65,976
Commercial Portfolio Segment
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	877,210
Allowance for loan and lease losses	(15,577)	$ 0
Loans and leases held for investment, net	$ 861,633
Allowance ratios	1.80%
Allowance for loan and lease losses to commercial loans and leases held for investment, excluding PPP loans, percent	2.60%
Commercial Portfolio Segment \| Equipment finance
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	$ 149,155
Commercial Portfolio Segment \| Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	310,399
Commercial Portfolio Segment \| Commercial and industrial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	417,656
Commercial Portfolio Segment \| Commercial and industrial loan, PPP
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases held for investment	$ 268,300

Financing Receivable, Allowance For Credit Loss To Outstanding, Excluding PPP Loans, Percent

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- Definition

Loans Pledged as Collateral Under The Federal Reserve Bank Discount Window

+ References

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- Definition

Percentage of allowance for credit loss to total financing receivable outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (1)

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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- Definition

Amount excluding accrued interest, before allowance for credit loss, of financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

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