Note 4 - Loans and Allowance for Loan Losses (Detail) - Recorded investment in loans, excluding loans acquired, by portfolio segment: (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Balance, end of period	$ 1,849,359	$ 1,922,119
Commercial Loans [Member] | Loans, excluding acquired loans [Member]
Loans individually evaluated for impairment	813	768
Loans collectively evaluated for impairment	217,642	234,373
Balance, end of period	218,455	235,141
Commercial Loans [Member]
Balance, end of period	218,455	235,141
Real Estate Loans [Member] | Loans, excluding acquired loans [Member]
Loans individually evaluated for impairment	23,413	28,358
Loans collectively evaluated for impairment	1,037,851	1,034,847
Balance, end of period	1,061,264	1,063,205
Real Estate Loans [Member]
Balance, end of period	1,061,264	1,063,205
Credit Cards [Member] | Loans, excluding acquired loans [Member]
Loans individually evaluated for impairment	494	547
Loans collectively evaluated for impairment	171,105	184,989
Balance, end of period	171,599	185,536
Other Consumer and Other Loans [Member] | Loans, excluding acquired loans [Member]
Loans individually evaluated for impairment	1,032	1,130
Loans collectively evaluated for impairment	136,727	143,501
Balance, end of period	137,759	144,631
Loans, excluding acquired loans [Member]
Loans individually evaluated for impairment	25,752	30,803
Loans collectively evaluated for impairment	1,563,325	1,597,710
Balance, end of period	$ 1,589,077	$ 1,628,513