Note 5 - Loans (Detail) - Troubled Debt Restructurings Modified (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
No. of Loans	61	32
Specific Reserve	$ 12,183,000	$ 7,554,000
Charge-off	46,000
Commercial Loans Member | Accruing Troubled Debt Restructuring Member
No. of Loans	9	7
Pre-Modification Recorded Investment	3,646,000	15,025,000
Post-Modification Recorded Investment	3,646,000	15,025,000
Specific Reserve	1,213,000	104,000
Commercial Mortgage Loans [Member] | Accruing Troubled Debt Restructuring Member
No. of Loans	20	6
Pre-Modification Recorded Investment	62,118,000	17,343,000
Post-Modification Recorded Investment	58,393,000	14,294,000
Specific Reserve	27,000	1,000
Charge-off	3,725,000	3,049,000
Residential Mortgage Loans [Member] | Accruing Troubled Debt Restructuring Member
No. of Loans	14	3
Pre-Modification Recorded Investment	4,305,000	1,574,000
Post-Modification Recorded Investment	4,223,000	1,574,000
Specific Reserve	162,000	114,000
Charge-off	82,000
Total [Member] | Accruing Troubled Debt Restructuring Member
No. of Loans	43	19
Pre-Modification Recorded Investment	70,069,000	67,611,000
Post-Modification Recorded Investment	66,262,000	52,415,000
Specific Reserve	1,402,000	219,000
Charge-off	3,807,000	15,196,000
Real Estate Construction Loans [Member] | Accruing Troubled Debt Restructuring Member
No. of Loans		3
Pre-Modification Recorded Investment		33,669,000
Post-Modification Recorded Investment		21,522,000
Charge-off		12,147,000
Accruing Troubled Debt Restructuring Member
Post-Modification Recorded Investment	144,695,000	120,016,000	136,800,000
Charge-off	$ (251,000)	$ (2,341,000)