Note 7 - Loans (Detail) - Non-accrual Troubled Debt Restructurings (Non Accruing Troubled Debt Restructuring Member, USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Non-accrual TDRs	$ 49,878	$ 47,731
Interest Deferral [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	1,606	1,685
Interest Deferral [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	267	275
Interest Deferral [Member]
Non-accrual TDRs	1,873	1,960
Real Estate Construction Loans [Member] | Commercial Loans Member
Non-accrual TDRs	2,425	912
Real Estate Construction Loans [Member] | Real Estate Construction Loans [Member]
Non-accrual TDRs	16,577	16,767
Real Estate Construction Loans [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	2,777	2,817
Real Estate Construction Loans [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	2,146	2,010
Real Estate Construction Loans [Member]
Non-accrual TDRs	23,925	22,506
Rate Reduction [Member] | Real Estate Construction Loans [Member]
Non-accrual TDRs	9,449	9,579
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	5,067	5,746
Rate Reduction [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	295	586
Rate Reduction [Member]
Non-accrual TDRs	14,811	15,911
Rate Reduction and Forgiveness of Principal [Member] | Commercial Loans Member
Non-accrual TDRs	1,475	1,518
Rate Reduction and Forgiveness of Principal [Member]
Non-accrual TDRs	1,475	1,518
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	7,088	5,076
Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	706	760
Rate Reduction and Payment Deferral [Member]
Non-accrual TDRs	7,794	5,836
Commercial Loans Member
Non-accrual TDRs	3,900	2,430
Real Estate Construction Loans [Member]
Non-accrual TDRs	26,026	26,346
Commercial Mortgage Loans [Member]
Non-accrual TDRs	16,538	15,324
Residential Mortgage Loans [Member]
Non-accrual TDRs	$ 3,414	$ 3,631