Note 16 - Regulatory Capital (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure Text Block [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

	Middlefield Banc Corp.					The Middlefield Banking Co.
(Dollar amounts in thousands)	December 31, 2014					December 31, 2014
	Amount		Ratio			Amount		Ratio
Total Capital (to Risk-weighted Assets)
Actual	$	70,693		14.64	%	$	68,325		14.19	%
For Capital Adequacy Purposes		38,642		8.00	%		38,507		8.00	%
To Be Well Capitalized		48,302		10.00	%		48,134		10.00	%
Tier I Capital (to Risk-weighted Assets)
Actual	$	64,645		13.38	%	$	62,315		12.95	%
For Capital Adequacy Purposes		19,321		4.00	%		19,253		4.00	%
To Be Well Capitalized		28,981		6.00	%		28,880		6.00	%
Tier I Capital (to Average Assets)
Actual	$	64,645		9.60	%	$	62,315		9.25	%
For Capital Adequacy Purposes		26,945		4.00	%		26,945		4.00	%
To Be Well Capitalized		33,682		5.00	%		33,682		5.00	%

	Middlefield Banc Corp.					The Middlefield Banking Co.					Emerald Bank
	December 31, 2013					December 31, 2013					December 31, 2013
	Amount		Ratio			Amount		Ratio			Amount		Ratio
Total Capital (to Risk-weighted Assets)
Actual	$	64,220		14.06	%	$	53,194		13.77	%	$	9,482		13.76	%
For Capital Adequacy Purposes		36,541		8.00	%		30,906		8.00	%		5,514		8.00	%
To Be Well Capitalized		45,676		10.00	%		38,632		10.00	%		6,893		10.00	%
Tier I Capital (to Risk-weighted Assets)
Actual	$	58,494		12.81	%	$	48,364		12.52	%	$	8,605		12.48	%
For Capital Adequacy Purposes		18,270		4.00	%		15,453		4.00	%		2,757		4.00	%
To Be Well Capitalized		27,406		6.00	%		23,179		6.00	%		4,136		6.00	%
Tier I Capital (to Average Assets)
Actual	$	58,494		8.97	%	$	48,364		8.51	%	$	8,605		10.92	%
For Capital Adequacy Purposes		26,093		4.00	%		22,735		4.00	%		3,152		4.00	%
To Be Well Capitalized		32,617		5.00	%		28,419		5.00	%		3,940		5.00	%