Note 4 - Investment Securities (Detail) - Temporarily Impaired Securities (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Securities Available-for-Sale
Investment Securities - Less than 12 Months - Fair Value	$ 102,668	$ 253,430
Investment Securities - Less than 12 Months - Unrealized Losses	2,538	14,586
Investment Securities - Less than 12 Months - No of Issuances	7	30
Investment Securities - 12 Months or longer - Fair Value	254,276	180,347
Investment Securities- 12 Months or longer - Unrealized Losses	11,612	18,204
Investment Securities - 12 Months or longer - No. of Issuances	34	28
Investment Securities - Fair Value	356,944	433,777
Investment Securities - Unrealized Losses	14,150	32,790
Investment Securities - No. of Issuances	41	58
Total [Member]
Securities Held-to-Maturity
Securities Held-to-maturity - Less than 12 Months - Fair Value	0	9,635
Securities Held-to-maturity - Less than 12 Months - Unrealized Losses	0	337
Securities Held-to-maturity - Less than 12 Months - No. of Issuances	0	1
Securities Held-to-maturity - 12 Months or longer - Fair Value	0	0
Securities Held-to-maturity - 12 Months or longer - Unrealized Losses	0	0
Securities Held-to-maturity - 12 Months or longer - No. of Issuances	0	0
Securities Held-to-maturity - Fair Value	0	9,635
Securities Held-to-maturity - Unrealized Losses	0	337
Securities Held-to-maturity - No. of Issuances	0	1
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	102,668	243,795
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	2,538	14,249
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	7	29
Securities Available-for-Sale - 12 Months or longer - Fair Value	254,276	180,347
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	11,612	18,204
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	34	28
Securities Available-for-Sale - Fair Value	356,944	424,142
Securities Available-for-Sale - Unrealized Losses	14,150	32,453
Securities Available-for-Sale - No. of Issuances	41	57
US Treasury Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	49,969
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	5
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	1
Securities Available-for-Sale - 12 Months or longer - Fair Value	0
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	0
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	0
Securities Available-for-Sale - Fair Value	49,969
Securities Available-for-Sale - Unrealized Losses	5
Securities Available-for-Sale - No. of Issuances	1
Collateralized Mortgage Backed Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	231	564
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	1	4
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	2	8
Securities Available-for-Sale - 12 Months or longer - Fair Value	170	35
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	1	1
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	6	2
Securities Available-for-Sale - Fair Value	401	599
Securities Available-for-Sale - Unrealized Losses	2	5
Securities Available-for-Sale - No. of Issuances	8	10
Mortgage Backed Securities Non Agency Member
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	0	0
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	0	0
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	0	0
Securities Available-for-Sale - 12 Months or longer - Fair Value	96	6,719
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	2	431
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	1	2
Securities Available-for-Sale - Fair Value	96	6,719
Securities Available-for-Sale - Unrealized Losses	2	431
Securities Available-for-Sale - No. of Issuances	1	2
Collateralized Mortgage Obligations [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	0	0
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	0	0
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	0	0
Securities Available-for-Sale - 12 Months or longer - Fair Value	439	570
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	35	238
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	4	4
Securities Available-for-Sale - Fair Value	439	570
Securities Available-for-Sale - Unrealized Losses	35	238
Securities Available-for-Sale - No. of Issuances	4	4
Asset-backed Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	0	0
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	0	0
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	0	0
Securities Available-for-Sale - 12 Months or longer - Fair Value	141	166
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	4	6
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	1	1
Securities Available-for-Sale - Fair Value	141	166
Securities Available-for-Sale - Unrealized Losses	4	6
Securities Available-for-Sale - No. of Issuances	1	1
Corporate Debt Securities [Member]
Securities Held-to-Maturity
Securities Held-to-maturity - Less than 12 Months - Fair Value		9,635
Securities Held-to-maturity - Less than 12 Months - Unrealized Losses		337
Securities Held-to-maturity - Less than 12 Months - No. of Issuances		1
Securities Held-to-maturity - 12 Months or longer - Fair Value		0
Securities Held-to-maturity - 12 Months or longer - Unrealized Losses		0
Securities Held-to-maturity - 12 Months or longer - No. of Issuances		0
Securities Held-to-maturity - Fair Value		9,635
Securities Held-to-maturity - Unrealized Losses		337
Securities Held-to-maturity - No. of Issuances		1
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	52,468	185,577
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	2,532	14,201
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	4	17
Securities Available-for-Sale - 12 Months or longer - Fair Value	253,430	172,857
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	11,570	17,528
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	22	19
Securities Available-for-Sale - Fair Value	305,898	358,434
Securities Available-for-Sale - Unrealized Losses	14,102	31,729
Securities Available-for-Sale - No. of Issuances	26	36
U.S. Government Sponsored Entities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value		49,993
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses		7
Securities Available-for-Sale - Less than 12 Months - No. of Issuances		1
Securities Available-for-Sale - 12 Months or longer - Fair Value		0
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses		0
Securities Available-for-Sale - 12 Months or longer - No. of Issuances		0
Securities Available-for-Sale - Fair Value		49,993
Securities Available-for-Sale - Unrealized Losses		7
Securities Available-for-Sale - No. of Issuances		1
Mutual Funds Member
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value		1,987
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses		13
Securities Available-for-Sale - Less than 12 Months - No. of Issuances		1
Securities Available-for-Sale - 12 Months or longer - Fair Value		0
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses		0
Securities Available-for-Sale - 12 Months or longer - No. of Issuances		0
Securities Available-for-Sale - Fair Value		1,987
Securities Available-for-Sale - Unrealized Losses		13
Securities Available-for-Sale - No. of Issuances		1
Trust Preferred Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value		5,674
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses		24
Securities Available-for-Sale - Less than 12 Months - No. of Issuances		2
Securities Available-for-Sale - 12 Months or longer - Fair Value		0
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses		0
Securities Available-for-Sale - 12 Months or longer - No. of Issuances		0
Securities Available-for-Sale - Fair Value		5,674
Securities Available-for-Sale - Unrealized Losses		$ 24
Securities Available-for-Sale - No. of Issuances		2