Note 7 - Loans (Details) - Aging of Loan Portfolio (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Type of Loans:
Loans, 30-59 Days Past Due	$ 9,054	$ 30,821
Loans, 60-89 Days Past Due	6,403	25,256
Loans, Greater than 90 Days Past Due	662	982
Non-accrual Loans	65,258	83,183
Loans, Past Due	81,377	140,242
Loans, Not Past Due	8,776,877	7,944,321
Loans	8,858,254	8,084,563
Commercial Loans [Member]
Type of Loans:
Loans, 30-59 Days Past Due	8,307	7,170
Loans, 60-89 Days Past Due	3,920	16,562
Loans, Greater than 90 Days Past Due	662
Non-accrual Loans	8,851	21,232
Loans, Past Due	21,740	44,964
Loans, Not Past Due	2,428,378	2,253,760
Loans	2,450,118	2,298,724
Real Estate Construction Loans [Member]
Type of Loans:
Non-accrual Loans	25,728	28,586
Loans, Past Due	25,728	28,586
Loans, Not Past Due	275,731	193,115
Loans	301,459	221,701
Commercial Mortgage Loans [Member]
Type of Loans:
Loans, 30-59 Days Past Due	171	20,043
Loans, 60-89 Days Past Due	1,676	7,862
Loans, Greater than 90 Days Past Due		982
Non-accrual Loans	23,830	19,621
Loans, Past Due	25,677	48,508
Loans, Not Past Due	4,388,390	3,974,543
Loans	4,414,067	4,023,051
Residential Mortgage And Equity Lines Member
Type of Loans:
Loans, 30-59 Days Past Due	408	3,508
Loans, 60-89 Days Past Due	807	832
Non-accrual Loans	6,849	13,744
Loans, Past Due	8,064	18,084
Loans, Not Past Due	1,680,870	1,508,448
Loans	1,688,934	1,526,532
Installment And Other Loans [Member]
Type of Loans:
Loans, 30-59 Days Past Due	168	100
Loans, Past Due	168	100
Loans, Not Past Due	3,508	14,455
Loans	$ 3,676	$ 14,555