Note 9 - Risk-Based Capital (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure Text Block [Abstract]

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

						For Capital Adequacy Purposes					To Be Well Capitalized Under the FDICIA Prompt Corrective Action Provisions
At December 31, 2013	Amount		Ratio			Amount		Ratio			Amount		Ratio
	(Dollars in thousands)
Total Capital (to risk-weighted assets)
Consolidated Company	$	446,331		16.18	%	$	220,745		8.00	%	$	275,931		10.00	%
Westamerica Bank		406,418		14.93	%		217,730		8.00	%		272,162		10.00	%
Tier 1 Capital (to risk-weighted assets)
Consolidated Company		405,798		14.71	%		110,372		4.00	%		165,559		6.00	%
Westamerica Bank		360,809		13.26	%		108,865		4.00	%		163,297		6.00	%
Leverage Ratio *
Consolidated Company		405,798		8.55	%		189,762		4.00	%		237,203		5.00	%
Westamerica Bank		360,809		7.67	%		188,109		4.00	%		235,137		5.00	%

						For Capital Adequacy Purposes					To Be Well Capitalized Under the FDICIA Prompt Corrective Action Provisions
At December 31, 2012	Amount		Ratio			Amount		Ratio			Amount		Ratio
	(Dollars in thousands)
Total Capital (to risk-weighted assets)
Consolidated Company	$	444,205		16.33	%	$	217,627		8.00	%	$	272,033		10.00	%
Westamerica Bank		418,746		15.62	%		214,452		8.00	%		268,065		10.00	%
Tier 1 Capital (to risk-weighted assets)
Consolidated Company		409,763		15.06	%		108,813		4.00	%		163,220		6.00	%
Westamerica Bank		378,921		14.14	%		107,226		4.00	%		160,839		6.00	%
Leverage Ratio *
Consolidated Company		409,763		8.56	%		191,396		4.00	%		239,245		5.00	%
Westamerica Bank		378,921		7.99	%		189,788		4.00	%		237,236		5.00	%