Document and Entity Information	3 Months Ended
	Mar. 31, 2012	Apr. 30, 2012
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Trading Symbol	TCFC
Entity Registrant Name	TRI COUNTY FINANCIAL CORP /MD/
Entity Central Index Key	0000855874
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		3,041,582