Loans and Allowance For Credit Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 15,957	$ 13,240	$ 14,081	$ 14,111
Provision for loan losses	800	300	2,675	(500)
Charge-offs	(202)	0	(202)	(278)
Recoveries		31	1	238
Ending balance	$ 16,555	$ 13,571	$ 16,555	$ 13,571
Net recoveries (charge-offs) / gross loans	(0.01%)	0.00%	(0.01%)	0.00%
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 9,526	$ 8,133	$ 8,552	$ 8,923
Provision for loan losses	699	45	1,672	(952)
Recoveries		31	1	238
Ending balance	$ 10,225	$ 8,209	$ 10,225	$ 8,209
Net recoveries (charge-offs) / gross loans	0.00%	0.01%	0.00%	0.06%
Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 5,243	$ 4,069	$ 4,524	$ 3,877
Provision for loan losses	(70)	324	649	516
Ending balance	$ 5,173	$ 4,393	$ 5,173	$ 4,393
Net recoveries (charge-offs) / gross loans	0.00%	0.00%	0.00%	0.00%
Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 907	$ 697	$ 681	$ 681
Provision for loan losses	90	(22)	316	(6)
Ending balance	$ 997	$ 675	$ 997	$ 675
Net recoveries (charge-offs) / gross loans	0.00%	0.00%	0.00%	0.00%
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 273	$ 317	$ 309	$ 604
Provision for loan losses	57	(44)	21	(53)
Charge-offs	(202)	0	(202)	(278)
Ending balance	$ 128	$ 273	$ 128	$ 273
Net recoveries (charge-offs) / gross loans	(2.36%)	0.00%	(2.36%)	(0.26%)
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 8	$ 24	$ 15	$ 26
Provision for loan losses	24	(3)	17	(5)
Ending balance	$ 32	$ 21	$ 32	$ 21
Net recoveries (charge-offs) / gross loans	0.00%	0.00%	0.00%	0.00%

Loans and Leases Receivable, Net Recoveries.

No definition available.

Name:	calb_LoansAndLeasesReceivableNetRecoveries
Namespace Prefix:	calb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(4)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI https://asc.fasb.org/extlink&oid=122038336&loc=d3e74567-122707

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI https://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_LoansAndLeasesReceivableDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=calb_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=calb_RealEstateConstructionAndLandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=calb_SmallBusinessAdministrationLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=calb_OtherLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: