Note 11 - Fair Value Measurements (Detail) - Financial Asset and Liabilities Measured on a Non-Recurring Basis (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Commercial Loans Member | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	$ 463		$ 0
Commercial Loans Member | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	859		877
Commercial Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Commercial Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Commercial Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	5,463		3,492
Commercial Loans Member | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	5,463		3,492
Commercial Mortgage Loans [Member] | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	41		440
Commercial Mortgage Loans [Member] | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	0		0
Commercial Mortgage Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Commercial Mortgage Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Commercial Mortgage Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	23,736		11,295
Commercial Mortgage Loans [Member] | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	23,736		11,295
Construction Residential Member | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	0		0
Construction Residential Member | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	0		0
Construction Residential Member | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Construction Residential Member | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Construction Residential Member | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	500		500
Construction Residential Member | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	500		500
Construction - Other Loans [Member] | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	0		65
Construction - Other Loans [Member] | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	0		0
Construction - Other Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Construction - Other Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Construction - Other Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	46,162		46,153
Construction - Other Loans [Member] | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	46,162		46,153
Real Estate Loans [Member] | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	0
Real Estate Loans [Member] | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	1,357
Real Estate Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0
Real Estate Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0
Real Estate Loans [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0
Real Estate Loans [Member] | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0
Residential Mortgage And Equity Lines Member | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	189		605
Residential Mortgage And Equity Lines Member | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	526		820
Residential Mortgage And Equity Lines Member | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Residential Mortgage And Equity Lines Member | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Residential Mortgage And Equity Lines Member | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	13,299		11,206
Residential Mortgage And Equity Lines Member | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	13,299		11,206
Land Loans Member | Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	48		162
Land Loans Member | Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	0		46
Land Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Land Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Land Loans Member | Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	208		297
Land Loans Member | Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	208		297
Current Period [Member] | Impaired Loans [Member]
Total Losses for the Year	741		1,272
Current Period [Member] | Other Real Estate Owned [Member]
Total Losses for the Year	(66)	[1]	10,904	[2]
Current Period [Member] | Investments in Venture Capital [Member]
Total Losses for the Year	92		309
Current Period [Member] | Equity Investments [Member]
Total Losses for the Year	0		181
Current Period [Member]
Total Losses for the Year	767		12,666
Prior Year [Member] | Impaired Loans [Member]
Total Losses for the Year	2,742		1,743
Prior Year [Member] | Other Real Estate Owned [Member]
Total Losses for the Year	2,824	[1]	7,003	[2]
Prior Year [Member] | Investments in Venture Capital [Member]
Total Losses for the Year	137		379
Prior Year [Member] | Equity Investments [Member]
Total Losses for the Year	0		200
Prior Year [Member]
Total Losses for the Year	5,703		9,325
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	89,368		72,943
Impaired Loans [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	89,368		72,943
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0	[1]	0	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	24,892	[1]	27,149	[2]
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	4,515	[1]	4,841	[2]
Other Real Estate Owned [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	29,407	[1]	31,990	[2]
Investments in Venture Capital [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Investments in Venture Capital [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Investments in Venture Capital [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	9,026		9,001
Investments in Venture Capital [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	9,026		9,001
Equity Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	142		142
Equity Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Equity Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	0		0
Equity Investments [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	142		142
Fair Value, Inputs, Level 1 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	142		142
Fair Value, Inputs, Level 2 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	24,892		27,149
Fair Value, Inputs, Level 3 [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	102,909		86,785
Estimate of Fair Value, Fair Value Disclosure [Member]
Assets Measured at Fair Value on a Nonrecurring Basis	$ 127,943		$ 114,076

[1] Other real estate owned balance of $45.3 million in the consolidated balance sheet is net of estimated disposal costs.

[2] Other real estate owned balance of $46.4 million in the consolidated balance sheet is net of estimated disposal costs.