Note 6 - Investment Securities (Detail) - Investment Securities With Unrealized Losses Not Recognized In Income (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
More 12 Months Unrealized Losses	$ 1,300
US Government-sponsored Enterprises Debt Securities [Member]
Less 12 Months Fair Value	7,872	13,494
Less 12 Months Unrealized Losses	2	15
Total Fair Value	7,872	13,494
Total Unrealized Losses	2	15
US States and Political Subdivisions Debt Securities [Member]
Less 12 Months Fair Value	4,882	2,913
Less 12 Months Unrealized Losses	36	20
More 12 Months Fair Value		6,886
More 12 Months Unrealized Losses		65
Total Fair Value	4,882	9,799
Total Unrealized Losses	36	85
Residential Mortgage Backed Securities [Member]
Less 12 Months Fair Value	7,259	56,249
Less 12 Months Unrealized Losses	38	196
Total Fair Value	7,259	56,249
Total Unrealized Losses	38	196
Corporate Debt Securities [Member]
More 12 Months Fair Value	4,548	4,299
More 12 Months Unrealized Losses	1,299	1,537
Total Fair Value	4,548	4,299
Total Unrealized Losses	1,299	1,537
Total [Member]
Less 12 Months Fair Value	20,013	72,656
Less 12 Months Unrealized Losses	76	231
More 12 Months Fair Value	4,548	11,185
More 12 Months Unrealized Losses	1,299	1,602
Total Fair Value	24,561	83,841
Total Unrealized Losses	$ 1,375	$ 1,833