Note 7 - Loans (Detail) - Non-accrual Troubled Debt Restructurings, Prior Year (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Interest Deferral [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	$ 2,584	$ 2,633
Interest Deferral [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	283	311
Interest Deferral [Member] | Total Non-Accrual TDRs [Member]
Non-accrual TDRs		2,944
Principal Deferral [Member] | Commercial Loans Member
Non-accrual TDRs	669	616
Principal Deferral [Member] | Real Estate Construction Loans [Member]
Non-accrual TDRs		13,579
Principal Deferral [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	1,140	9,727
Principal Deferral [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	1,600	2,427
Principal Deferral [Member] | Total Non-Accrual TDRs [Member]
Non-accrual TDRs		26,349
Rate Reduction [Member] | Commercial Loans Member
Non-accrual TDRs		1,859
Rate Reduction [Member] | Real Estate Construction Loans [Member]
Non-accrual TDRs		12,376
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	5,743
Rate Reduction [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	595	449
Rate Reduction [Member] | Total Non-Accrual TDRs [Member]
Non-accrual TDRs		14,684
Rate Reduction and Forgiveness of Principal [Member] | Commercial Loans Member
Non-accrual TDRs		1,506
Rate Reduction and Forgiveness of Principal [Member] | Total Non-Accrual TDRs [Member]
Non-accrual TDRs		1,506
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Non-accrual TDRs	6,123	5,076
Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Non-accrual TDRs	339	311
Rate Reduction and Payment Deferral [Member] | Total Non-Accrual TDRs [Member]
Non-accrual TDRs		5,387
Commercial Loans Member
Non-accrual TDRs	669	3,981
Real Estate Construction Loans [Member]
Non-accrual TDRs		25,955
Commercial Mortgage Loans [Member]
Non-accrual TDRs	15,590	17,436
Residential Mortgage Loans [Member]
Non-accrual TDRs	2,817	3,498
Total Non-Accrual TDRs [Member]
Non-accrual TDRs		$ 50,870