Loans And Leases (Activity In ALLL By Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 15,495	$ 10,107	$ 17,022	$ 7,138
Addition to (reduction in) provision for loan losses		5,750	(1,600)	8,875
Charge-offs	(17)	(371)	(17)	(539)
Recoveries	9	6	82	18
Ending balance	15,487	15,492	15,487	15,492
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,377	2,664	3,426	2,054
Addition to (reduction in) provision for loan losses	200	610	95	1,330
Charge-offs				(110)
Recoveries			56
Ending balance	3,577	3,274	3,577	3,274
Single-Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	2,431	999	1,299	948
Addition to (reduction in) provision for loan losses	365	500	1,490	605
Charge-offs	(17)	(350)	(17)	(408)
Recoveries	4	1	11	5
Ending balance	2,783	1,150	2,783	1,150
Multi-Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	777	567	467	447
Addition to (reduction in) provision for loan losses	150		460	120
Charge-offs
Recoveries
Ending balance	927	567	927	567
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	6,834	4,534	9,184	2,604
Addition to (reduction in) provision for loan losses	(550)	4,400	(2,900)	6,330
Charge-offs
Recoveries
Ending balance	6,284	8,934	6,284	8,934
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	1,679	1,024	2,254	759
Addition to (reduction in) provision for loan losses	(200)	250	(775)	515
Charge-offs
Recoveries
Ending balance	1,479	1,274	1,479	1,274
Home Equity Lines Of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	236	263	276	265
Addition to (reduction in) provision for loan losses	25		(25)	(10)
Charge-offs		(21)		(21)
Recoveries	5	5	15	13
Ending balance	266	247	266	247
Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	161	56	116	61
Addition to (reduction in) provision for loan losses	10	(10)	55	(15)
Charge-offs
Recoveries
Ending balance	$ 171	$ 46	$ 171	$ 46

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

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

+ Details

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

- 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_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: 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 http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544

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)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

+ Details

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

- 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 http://asc.fasb.org/extlink&oid=121586364&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 http://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 http://asc.fasb.org/extlink&oid=121611835&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=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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