Segment Reporting (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting [Abstract]
Number of principal business activities			3
Line of credit	$ 5,000,000		$ 5,000,000
Participating agreement	75,000,000		75,000,000
Revenue [Abstract]
Interest Income	11,407,000	12,231,000	35,563,000	36,210,000
Trust and investment fee income	1,045,000	1,032,000	3,219,000	3,018,000
Other income	7,273,000	4,815,000	18,254,000	11,269,000
Total operating income	19,725,000	18,078,000	57,036,000	50,497,000
Expense [Abstract]
Interest Expense	2,190,000	2,741,000	6,917,000	8,224,000
Salaries and employee benefits	7,276,000	6,900,000	22,139,000	19,665,000
Provision for loan losses	635,000	1,024,000	2,156,000	2,565,000
Other	6,560,000	5,338,000	18,324,000	15,275,000
Total operating expenses	16,661,000	16,003,000	49,536,000	45,729,000
Income (loss) before income taxes and non-controlling interest	3,064,000	2,075,000	7,500,000	4,768,000
Income tax expense	565,000	454,000	1,578,000	1,072,000
NET INCOME	2,499,000	1,621,000	5,922,000	3,696,000
Non-controlling interest in loss of consolidated subsidiary	(785,000)	(223,000)	(856,000)	128,000
Net income attributable to Middleburg Financial Corporation	1,714,000	1,398,000	5,066,000	3,824,000
Total assets	1,235,961,000	1,153,656,000	1,235,961,000	1,153,656,000	1,192,860,000
Capital Expenditure	6,000	736,000	541,000	1,430,000
Goodwill and other intangibles	6,060,000	6,244,000	6,060,000	6,244,000
Retail Banking [Member]
Revenue [Abstract]
Interest Income	11,262,000	11,956,000	34,837,000	35,076,000
Trust and investment fee income	0	0	0	0
Other income	1,046,000	970,000	2,960,000	2,898,000
Total operating income	12,308,000	12,926,000	37,797,000	37,974,000
Expense [Abstract]
Interest Expense	2,115,000	2,684,000	6,606,000	8,051,000
Salaries and employee benefits	3,722,000	4,070,000	11,395,000	11,450,000
Provision for loan losses	570,000	1,100,000	2,127,000	2,641,000
Other	5,146,000	3,691,000	13,191,000	10,940,000
Total operating expenses	11,553,000	11,545,000	33,319,000	33,082,000
Income (loss) before income taxes and non-controlling interest	755,000	1,381,000	4,478,000	4,892,000
Income tax expense	472,000	381,000	1,277,000	986,000
NET INCOME	283,000	1,000,000	3,201,000	3,906,000
Non-controlling interest in loss of consolidated subsidiary	0	0	0	0
Net income attributable to Middleburg Financial Corporation	283,000	1,000,000	3,201,000	3,906,000
Total assets	1,209,455,000	1,139,348,000	1,209,455,000	1,139,348,000
Capital Expenditure	6,000	585,000	541,000	1,276,000
Goodwill and other intangibles	0	0	0	0
Wealth Management [Member]
Revenue [Abstract]
Interest Income	2,000	2,000	7,000	8,000
Trust and investment fee income	1,080,000	1,032,000	3,323,000	3,018,000
Other income	0	0	0	0
Total operating income	1,082,000	1,034,000	3,330,000	3,026,000
Expense [Abstract]
Interest Expense	0	0	0	0
Salaries and employee benefits	548,000	608,000	1,628,000	1,921,000
Provision for loan losses	0	0	0	0
Other	309,000	321,000	951,000	962,000
Total operating expenses	857,000	929,000	2,579,000	2,883,000
Income (loss) before income taxes and non-controlling interest	225,000	105,000	751,000	143,000
Income tax expense	93,000	73,000	301,000	86,000
NET INCOME	132,000	32,000	450,000	57,000
Non-controlling interest in loss of consolidated subsidiary	0	0	0	0
Net income attributable to Middleburg Financial Corporation	132,000	32,000	450,000	57,000
Total assets	12,789,000	12,378,000	12,789,000	12,378,000
Capital Expenditure	0	0	0	3,000
Goodwill and other intangibles	4,193,000	4,377,000	4,193,000	4,377,000
Mortgage Banking [Member]
Revenue [Abstract]
Interest Income	630,000	617,000	2,067,000	2,008,000
Trust and investment fee income	0	0	0	0
Other income	6,307,000	3,846,000	15,719,000	8,373,000
Total operating income	6,937,000	4,463,000	17,786,000	10,381,000
Expense [Abstract]
Interest Expense	562,000	401,000	1,659,000	1,055,000
Salaries and employee benefits	3,006,000	2,222,000	9,116,000	6,294,000
Provision for loan losses	65,000	(76,000)	29,000	(76,000)
Other	1,220,000	1,327,000	4,711,000	3,375,000
Total operating expenses	4,853,000	3,874,000	15,515,000	10,648,000
Income (loss) before income taxes and non-controlling interest	2,084,000	589,000	2,271,000	(267,000)
Income tax expense	0	0	0	0
NET INCOME	2,084,000	589,000	2,271,000	(267,000)
Non-controlling interest in loss of consolidated subsidiary	(785,000)	(223,000)	(856,000)	128,000
Net income attributable to Middleburg Financial Corporation	1,299,000	366,000	1,415,000	(139,000)
Total assets	104,919,000	77,177,000	104,919,000	77,177,000
Capital Expenditure	0	151,000	0	151,000
Goodwill and other intangibles	1,867,000	1,867,000	1,867,000	1,867,000
Intercompany Eliminations [Member]
Revenue [Abstract]
Interest Income	(487,000)	(344,000)	(1,348,000)	(882,000)
Trust and investment fee income	(35,000)	0	(104,000)	0
Other income	(80,000)	(1,000)	(425,000)	(2,000)
Total operating income	(602,000)	(345,000)	(1,877,000)	(884,000)
Expense [Abstract]
Interest Expense	(487,000)	(344,000)	(1,348,000)	(882,000)
Salaries and employee benefits	0	0	0	0
Provision for loan losses	0	0	0	0
Other	(115,000)	(1,000)	(529,000)	(2,000)
Total operating expenses	(602,000)	(345,000)	(1,877,000)	(884,000)
Income (loss) before income taxes and non-controlling interest	0	0	0	0
Income tax expense	0	0	0	0
NET INCOME	0	0	0	0
Non-controlling interest in loss of consolidated subsidiary	0	0	0	0
Net income attributable to Middleburg Financial Corporation	0	0	0	0
Total assets	(91,202,000)	(75,247,000)	(91,202,000)	(75,247,000)
Capital Expenditure	0	0	0
Goodwill and other intangibles	$ 0	$ 0	$ 0	$ 0