Note 7 - Loans (Detail) - Schedule of Aging of Loan Portfolio (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Total	$ 6,908,544	$ 7,059,212
Commercial Loans Member
30-59 Days Past Due	16,248	1,683
60-89 Days Past Due	605	0
Greater than 90 Days Past Due	845	0
Non-accrual Loans	30,329	30,661
Total Past Due	48,027	32,344
Loans Not Past Due	1,796,822	1,835,931
Total	1,844,849	1,868,275
Real Estate Construction Loans [Member]
30-59 Days Past Due	22,674	20,326
60-89 Days Past Due	3,553	0
Greater than 90 Days Past Due	0	0
Non-accrual Loans	10,711	46,012
Total Past Due	36,938	66,338
Loans Not Past Due	151,143	171,034
Total	188,081	237,372
Commercial Mortgage Loans [Member]
30-59 Days Past Due	11,718	13,627
60-89 Days Past Due	591	20,277
Greater than 90 Days Past Due	544	6,726
Non-accrual Loans	76,619	107,784
Total Past Due	89,472	148,414
Loans Not Past Due	3,572,964	3,600,483
Total	3,662,436	3,748,897
Residential Mortgage And Equity Lines Member
30-59 Days Past Due	6,175	5,871
60-89 Days Past Due	668	0
Greater than 90 Days Past Due	0	0
Non-accrual Loans	13,838	16,740
Total Past Due	20,681	22,611
Loans Not Past Due	1,173,026	1,164,358
Total	1,193,707	1,186,969
Installment And Other Loans Member
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater than 90 Days Past Due	0	0
Non-accrual Loans	0	0
Total Past Due	0	0
Loans Not Past Due	19,471	17,699
Total	19,471	17,699
Total [Member]
30-59 Days Past Due	56,815	41,507
60-89 Days Past Due	5,417	20,277
Greater than 90 Days Past Due	1,389	6,726
Non-accrual Loans	131,497	201,197
Total Past Due	195,118	269,707
Loans Not Past Due	6,713,426	6,789,505
Total	$ 6,908,544	$ 7,059,212