Note 4 - Investment Securities (Detail) - Investment Securities - Unrealized Loss (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fair value less than 12 months	$ 7,254	$ 3,294
Unrealized losses less than 12 months	46	43
Fair value	7,254	3,294
Unrealized losses	46	43
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Fair value less than 12 months	1,653	3,294
Unrealized losses less than 12 months	20	43
Fair value 12 months or more		0
Unrealized losses 12 months or more		0
Fair value	1,653	3,294
Unrealized losses	20	43
Collateralized Mortgage Obligations [Member]
Fair value less than 12 months	1,656
Unrealized losses less than 12 months	1
Fair value	1,656
Unrealized losses	1
Municipal Securities [Member]
Fair value less than 12 months	3,945
Unrealized losses less than 12 months	25
Fair value	3,945
Unrealized losses	$ 25