Note 4 - Investment Securities (Detail) - Held to Maturity Securities With Temporary Unrealized Loss Position (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Held to maturity securities continuous unrealized loss position less than 12 months fair value	$ 48,116	$ 15,727
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses	88	18
Held to maturity securities continuous unrealized loss position 12 months or longer fair value		289
Held to maturity securities continuous unrealized loss position 12 months or longer unrealized losses		1
Held to maturity securities continuous unrealized loss position fair value	48,116	16,016
Held to maturity securities continuous unrealized loss unrealized losses	88	19
Federal National Mortgage Association Agency Notes [Member]
Held to maturity securities continuous unrealized loss position less than 12 months fair value	14,926
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses	74
Held to maturity securities continuous unrealized loss position fair value	14,926
Held to maturity securities continuous unrealized loss unrealized losses	74
Federal Home Loan Bank Agency Notes [Member]
Held to maturity securities continuous unrealized loss position less than 12 months fair value	32,987
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses	12
Held to maturity securities continuous unrealized loss position fair value	32,987
Held to maturity securities continuous unrealized loss unrealized losses	12
Obligations of U.S. Government Corporations and Government Sponsored Enterprises [Member]
Held to maturity securities continuous unrealized loss position less than 12 months fair value	47,913	14,991
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses	86	9
Held to maturity securities continuous unrealized loss position fair value	47,913	14,991
Held to maturity securities continuous unrealized loss unrealized losses	86	9
Obligations of State and Political Institutions - New York Bank Qualified [Member]
Held to maturity securities continuous unrealized loss position less than 12 months fair value	203	736
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses	2	9
Held to maturity securities continuous unrealized loss position 12 months or longer fair value		289
Held to maturity securities continuous unrealized loss position 12 months or longer unrealized losses		1
Held to maturity securities continuous unrealized loss position fair value	203	1,025
Held to maturity securities continuous unrealized loss unrealized losses	2	10
Federal Home Loan Mortgage Corporation Agency Notes [Member]
Held to maturity securities continuous unrealized loss position less than 12 months fair value		14,991
Held to maturity securities continuous unrealized loss position less than 12 months unrealized losses		9
Held to maturity securities continuous unrealized loss position fair value		14,991
Held to maturity securities continuous unrealized loss unrealized losses		$ 9