Note 7 - Loans (Detail) - Allowance for Loan Losses by Portfolio Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Provision for possible credit losses			$ 10,362	$ 9,088
Commercial Loans Member
Ending Balance	65,738	63,788	65,738	63,788
Reserve for impaired loans	1,791	2,270	1,791	2,270
Reserve for non-impaired loans	63,947	61,518	63,947	61,518
Reserve for off-balance sheet credit commitments	801	757	801	757
Beginning Balance	66,595	65,860	65,658	63,919
Provision for possible credit losses	6,199	(1,366)	13,329	9,516
Charge-offs	(7,387)	(1,219)	(14,479)	(11,215)
Recoveries	331	513	1,230	1,568
Net charge-offs	(7,056)	(706)	(13,249)	(9,647)
Real Estate Construction Loans [Member]
Ending Balance	16,128	23,876	16,128	23,876
Reserve for impaired loans	279		279
Reserve for non-impaired loans	15,849	23,876	15,849	23,876
Reserve for off-balance sheet credit commitments	668	967	668	967
Beginning Balance	16,360	37,683	21,749	43,261
Provision for possible credit losses	(670)	9,324	(10,081)	10,713
Charge-offs	(39)	(23,539)	(1,165)	(34,394)
Recoveries	477	408	5,625	4,296
Net charge-offs	438	(23,131)	4,460	(30,098)
Commercial Mortgage Loans [Member]
Ending Balance	92,011	113,074	92,011	113,074
Reserve for impaired loans	1,729	3,930	1,729	3,930
Reserve for non-impaired loans	90,282	109,144	90,282	109,144
Reserve for off-balance sheet credit commitments	104	103	104	103
Beginning Balance	99,009	117,014	108,021	128,347
Provision for possible credit losses	(6,350)	951	(12,937)	5,704
Charge-offs	(966)	(5,264)	(10,647)	(24,083)
Recoveries	318	373	7,574	3,106
Net charge-offs	(648)	(4,891)	(3,073)	(20,977)
Residential Mortgage And Equity Lines Member
Ending Balance	10,528	8,343	10,528	8,343
Reserve for impaired loans	1,626	1,203	1,626	1,203
Reserve for non-impaired loans	8,902	7,140	8,902	7,140
Reserve for off-balance sheet credit commitments	34	34	34	34
Beginning Balance	10,254	9,307	10,795	9,668
Provision for possible credit losses	740	(224)	1,150	(458)
Charge-offs	(477)	(818)	(1,805)	(1,044)
Recoveries	11	78	388	177
Net charge-offs	(466)	(740)	(1,417)	(867)
Installment And Other Loans Member
Ending Balance	33	35	33	35
Reserve for impaired loans	0		0
Reserve for non-impaired loans	33	35	33	35
Reserve for off-balance sheet credit commitments	3	2	3	2
Beginning Balance	56	36	57	36
Provision for possible credit losses	(23)	(1)	(2)	(1)
Charge-offs			(25)
Recoveries			3
Net charge-offs			(22)
Total [Member]
Ending Balance	184,438	209,116	184,438	209,116
Reserve for impaired loans	5,425	7,403	5,425	7,403
Reserve for non-impaired loans	179,013	201,713	179,013	201,713
Reserve for off-balance sheet credit commitments	1,610	1,863	1,610	1,863
Beginning Balance	192,274	229,900	206,280	245,231
Provision for possible credit losses	(104)	8,684	(8,541)	25,474
Charge-offs	(8,869)	(30,840)	(28,121)	(70,736)
Recoveries	1,137	1,372	14,820	9,147
Net charge-offs	$ (7,732)	$ (29,468)	$ (13,301)	$ (61,589)