Note 7 - Loans (Detail) - Troubled Debt Restructuring by Type of Concession and Type of Loans (Accruing Troubled Debt Restructuring Member, USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accruing TDRs	$ 130,215	$ 144,695
Principal Deferral [Member] | Commercial Loans Member
Accruing TDRs	491	531
Principal Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	0	0
Principal Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	27,565	27,003
Principal Deferral [Member] | Residential Construction [Member]
Accruing TDRs	1,455	1,461
Principal Deferral [Member]
Accruing TDRs	29,511	28,995
Rate Reduction [Member] | Commercial Loans Member
Accruing TDRs	2,994	3,020
Rate Reduction [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	0	0
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	16,153	16,656
Rate Reduction [Member] | Residential Construction [Member]
Accruing TDRs	1,604	1,024
Rate Reduction [Member]
Accruing TDRs	20,751	20,700
Rate Reduction and Payment Deferral [Member] | Commercial Loans Member
Accruing TDRs	2,797	413
Rate Reduction and Payment Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	5,834	5,834
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	67,812	85,783
Rate Reduction and Payment Deferral [Member] | Residential Construction [Member]
Accruing TDRs	3,510	2,231
Rate Reduction and Payment Deferral [Member]
Accruing TDRs	79,953	94,261
Rate Reduction and Forgiveness of Principal [Member] | Commercial Loans Member
Accruing TDRs		0
Rate Reduction and Forgiveness of Principal [Member] | Real Estate Construction Loans [Member]
Accruing TDRs		0
Rate Reduction and Forgiveness of Principal [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs		739
Rate Reduction and Forgiveness of Principal [Member] | Residential Construction [Member]
Accruing TDRs		0
Rate Reduction and Forgiveness of Principal [Member]
Accruing TDRs		739
Commercial Loans Member
Accruing TDRs	6,282	3,964
Real Estate Construction Loans [Member]
Accruing TDRs	5,834	5,834
Commercial Mortgage Loans [Member]
Accruing TDRs	111,530	130,181
Residential Construction [Member]
Accruing TDRs	$ 6,569	$ 4,716