Note 5 - Loans (Detail) - Troubled Debt Restructuring by Type of Concession and Type of Loans (USD $)	Dec. 31, 2012	Dec. 31, 2011
Accruing TDRs	$ 144,695,000	$ 120,016,000
Accruing Troubled Debt Restructuring Member | Principal Deferral [Member] | Commercial Loans Member
Accruing TDRs	531,000	12,933,000
Accruing Troubled Debt Restructuring Member | Principal Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs		16,820,000
Accruing Troubled Debt Restructuring Member | Principal Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	27,003,000	471,000
Accruing Troubled Debt Restructuring Member | Principal Deferral [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	1,461,000	1,294,000
Accruing Troubled Debt Restructuring Member | Principal Deferral [Member]
Accruing TDRs	28,995,000	31,518,000
Accruing Troubled Debt Restructuring Member | Rate Reduction [Member] | Commercial Loans Member
Accruing TDRs	3,020,000	1,756,000
Accruing Troubled Debt Restructuring Member | Rate Reduction [Member] | Real Estate Construction Loans [Member]
Accruing TDRs		9,659,000
Accruing Troubled Debt Restructuring Member | Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	16,656,000	37,796,000
Accruing Troubled Debt Restructuring Member | Rate Reduction [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	1,024,000	587,000
Accruing Troubled Debt Restructuring Member | Rate Reduction [Member]
Accruing TDRs	20,700,000	49,798,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Forgiveness of Principal [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	739,000	2,071,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Forgiveness of Principal [Member]
Accruing TDRs	739,000	2,071,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Payment Deferral [Member] | Commercial Loans Member
Accruing TDRs	413,000	431,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Payment Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	5,834,000	5,776,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	85,783,000	28,935,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	2,231,000	1,487,000
Accruing Troubled Debt Restructuring Member | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	94,261,000	36,629,000
Commercial Loans Member
Accruing TDRs	3,964,000	15,120,000
Real Estate Construction Loans [Member]
Accruing TDRs	5,834,000	32,255,000
Commercial Mortgage Loans [Member]
Accruing TDRs	130,181,000	69,273,000
Residential Mortgage Loans [Member]
Accruing TDRs	$ 4,716,000	$ 3,368,000