Deposits (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019 USD ($) customer	Dec. 31, 2018 USD ($) customer
Deposits	$ 1,439,167	$ 1,429,629
Time deposits $250000 or more	135,100	117,200
Customer Concentration Risk [Member] \| Sales Revenue, Net [Member]
Deposits	$ 136,000	$ 158,800
Concentration risk, percentage	2.00%	2.00%
Concentration risk, customer with deposits exceeding threshold \| customer	1	1
Concentration risk percentage of total deposits	9.45%	11.10%

Concentration risk, customer with deposits exceeding threshold.

No definition available.

Name:	tcfc_ConcentrationRiskCustomerWithDepositsExceedingThreshold
Namespace Prefix:	tcfc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Concentration risk percentage of total deposits.

+ References

No definition available.

+ Details

Name:	tcfc_ConcentrationRiskPercentageOfTotalDeposits
Namespace Prefix:	tcfc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

" The aggregate amount of domestic and foreign time deposit liabilities (including certificates of deposits, individual retirement accounts and open accounts) in denominations of $250,000 or more."

+ References

No definition available.

+ Details

Name:	tcfc_TimeDeposits250000OrMore
Namespace Prefix:	tcfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: