Note 4 - Debt and Equity Securities (Detail) - Securities available for sale: (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Amortized Cost	$ 974,139	$ 915,947
Fair Value	1,000,294	949,566
Gross Unrealized Gains	33,692	41,391
Gross Unrealized Losses	7,537	7,772
US Government Agencies Debt Securities [Member]
Amortized Cost	10,006	31,409
Fair Value	10,020	31,513
Gross Unrealized Gains	14	104
Corporate Debt Securities [Member]
Amortized Cost	103,668	83,389
Fair Value	108,323	87,485
Gross Unrealized Gains	4,674	4,096
Gross Unrealized Losses	19
Municipal [Member]
Amortized Cost	81,113	74,228
Fair Value	81,200	75,297
Gross Unrealized Gains	417	1,152
Gross Unrealized Losses	330	83
Mutual Funds [Member]
Amortized Cost	21,823	21,843
Fair Value	21,823	21,843
Other Debt Obligations [Member]
Amortized Cost	18,172	17,797
Fair Value	14,227	13,315
Gross Unrealized Gains	17	17
Gross Unrealized Losses	3,962	4,499
Available For Sale Securities Excluding Mortgage Backed Securities [Member]
Amortized Cost	234,782	228,666
Fair Value	235,593	229,453
Gross Unrealized Gains	5,122	5,369
Gross Unrealized Losses	4,311	4,582
REMIC And CMO [Member]
Amortized Cost	492,492	453,468
Fair Value	509,440	474,050
Gross Unrealized Gains	19,445	23,690
Gross Unrealized Losses	2,497	3,108
GNMA [Member]
Amortized Cost	37,487	43,211
Fair Value	40,843	46,932
Gross Unrealized Gains	3,356	3,721
FNMA [Member]
Amortized Cost	193,310	168,040
Fair Value	197,903	175,929
Gross Unrealized Gains	5,322	7,971
Gross Unrealized Losses	729	82
FHLMC [Member]
Amortized Cost	16,068	22,562
Fair Value	16,515	23,202
Gross Unrealized Gains	447	640
Collateralized Mortgage Backed Securities [Member]
Amortized Cost	739,357	687,281
Fair Value	764,701	720,113
Gross Unrealized Gains	28,570	36,022
Gross Unrealized Losses	$ 3,226	$ 3,190

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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