Note 7 - Loans (Detail) - Troubled Debt Restructuring by Type of Concession and Type of Loans (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Principal Deferral [Member] | Commercial Loans Member
Accruing TDRs	$ 553	$ 12,933
Principal Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	16,820	16,820
Principal Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	27,091	471
Principal Deferral [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	1,465	1,294
Principal Deferral [Member] | Total [Member]
Accruing TDRs	45,929	31,518
Rate Reduction [Member] | Commercial Loans Member
Accruing TDRs	3,044	1,756
Rate Reduction [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	9,581	9,659
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	16,597	37,796
Rate Reduction [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	1,027	587
Rate Reduction [Member] | Total [Member]
Accruing TDRs	30,249	49,798
Rate Reduction and Forgiveness of Principal [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	1,138	2,071
Rate Reduction and Forgiveness of Principal [Member] | Total [Member]
Accruing TDRs	1,138	2,071
Rate Reduction and Payment Deferral [Member] | Commercial Loans Member
Accruing TDRs	418	431
Rate Reduction and Payment Deferral [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	5,834	5,776
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	84,829	28,935
Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	1,754	1,487
Rate Reduction and Payment Deferral [Member] | Total [Member]
Accruing TDRs	92,835	36,629
Total Accruing TDR's [Member] | Commercial Loans Member
Accruing TDRs	4,015	15,120
Total Accruing TDR's [Member] | Real Estate Construction Loans [Member]
Accruing TDRs	32,235	32,255
Total Accruing TDR's [Member] | Commercial Mortgage Loans [Member]
Accruing TDRs	129,655	69,273
Total Accruing TDR's [Member] | Residential Mortgage Loans [Member]
Accruing TDRs	4,246	3,368
Total Accruing TDR's [Member] | Total [Member]
Accruing TDRs	$ 170,151	$ 120,016