Note 4 - Loans and Allowance for Credit Losses (Detail) - Loans receivable at carrying amount (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Originated loans	$ 1,664,183	$ 1,862,607
Purchased covered loans	372,283	535,278
Purchased non-covered loans	74,891	125,921
Total	2,111,357	2,523,806
Impaired [Member] | Commercial Portfolio Segment [Member]
Purchased covered loans	308	1,296
Purchased non-covered loans	1,261	2,262
Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Purchased covered loans	7,585	20,697
Purchased non-covered loans	6,763	17,090
Impaired [Member] | Construction Portfolio Segment [Member]
Purchased covered loans	1,824	2,977
Impaired [Member] | Consumer Portfolio Segment [Member]
Purchased covered loans	257	262
Purchased non-covered loans	297	638
Impaired [Member]
Purchased covered loans	9,974	25,232
Purchased non-covered loans	8,321	19,990
Non Impaired [Member] | Commercial Portfolio Segment [Member]
Purchased covered loans	59,135	117,777
Purchased non-covered loans	9,840	14,129
Non Impaired [Member] | Commercial Real Estate Portfolio Segment [Member]
Purchased covered loans	247,534	333,428
Purchased non-covered loans	38,673	67,045
Non Impaired [Member] | Construction Portfolio Segment [Member]
Purchased covered loans	5,462	13,372
Purchased non-covered loans	1,619	6,076
Non Impaired [Member] | Residential Portfolio Segment [Member]
Purchased covered loans	9,374	13,016
Purchased non-covered loans	3,110	3,598
Non Impaired [Member] | Consumer Portfolio Segment [Member]
Purchased covered loans	66,932	78,735
Purchased non-covered loans	18,554	25,294
Non Impaired [Member]
Purchased covered loans	388,437	556,328
Purchased non-covered loans	71,796	116,142
Purchase Discount [Member] | Commercial Portfolio Segment [Member]
Purchased covered loans	(8,459)	(19,535)
Purchased non-covered loans	(870)	(1,013)
Purchase Discount [Member] | Commercial Real Estate Portfolio Segment [Member]
Purchased covered loans	(15,140)	(22,318)
Purchased non-covered loans	(1,748)	(6,101)
Purchase Discount [Member] | Construction Portfolio Segment [Member]
Purchased covered loans	(279)	(2,473)
Purchased non-covered loans	(95)	(95)
Purchase Discount [Member] | Residential Portfolio Segment [Member]
Purchased covered loans	(433)	(524)
Purchased non-covered loans	(474)	(474)
Purchase Discount [Member] | Consumer Portfolio Segment [Member]
Purchased covered loans	(1,817)	(1,432)
Purchased non-covered loans	(2,039)	(2,528)
Purchase Discount [Member]
Purchased covered loans	(26,128)	(46,282)
Purchased non-covered loans	(5,226)	(10,211)
Commercial Portfolio Segment [Member]
Originated loans	340,116	398,446
Total	401,331	513,362
Commercial Real Estate Portfolio Segment [Member]
Originated loans	632,927	704,655
Total	916,594	1,114,496
Construction Portfolio Segment [Member]
Originated loans	7,984	14,580
Total	16,515	34,437
Residential Portfolio Segment [Member]
Originated loans	222,458	271,111
Total	234,035	286,727
Consumer Portfolio Segment [Member]
Originated loans	460,698	473,815
Total	$ 542,882	$ 574,784