Note 4 - Debt and Equity Securities (Details) - Securities available for sale: (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	$ 1,041,834	$ 915,947
Fair Value	1,040,723	949,566
Gross Unrealized Gains	20,531	41,391
Gross Unrealized Losses	21,642	7,772
Corporate Debt Securities [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	128,480	83,389
Fair Value	131,665	87,485
Gross Unrealized Gains	3,890	4,096
Gross Unrealized Losses	705
Municipal [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	94,859	74,228
Fair Value	90,607	75,297
Gross Unrealized Gains		1,152
Gross Unrealized Losses	4,252	83
Mutual Funds [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	21,496	21,843
Fair Value	21,496	21,843
Other Debt Obligations [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	17,858	17,797
Fair Value	14,567	13,315
Gross Unrealized Gains		17
Gross Unrealized Losses	3,291	4,499
Available For Sale Securities Excluding Mortgage Backed Securities [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	262,693	228,666
Fair Value	258,335	229,453
Gross Unrealized Gains	3,890	5,369
Gross Unrealized Losses	8,248	4,582
REMIC And CMO [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	521,549	453,468
Fair Value	525,094	474,050
Gross Unrealized Gains	11,091	23,690
Gross Unrealized Losses	7,546	3,108
GNMA [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	44,266	43,211
Fair Value	46,484	46,932
Gross Unrealized Gains	2,569	3,721
Gross Unrealized Losses	351
FNMA [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	198,488	168,040
Fair Value	195,866	175,929
Gross Unrealized Gains	2,742	7,971
Gross Unrealized Losses	5,364	82
FHLMC [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	14,838	22,562
Fair Value	14,944	23,202
Gross Unrealized Gains	239	640
Gross Unrealized Losses	133
Collateralized Mortgage Backed Securities [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost	779,141	687,281
Fair Value	782,388	720,113
Gross Unrealized Gains	16,641	36,022
Gross Unrealized Losses	13,394	3,190
US Government Agencies Debt Securities [Member]
Note 4 - Debt and Equity Securities (Details) - Securities available for sale: [Line Items]
Amortized Cost		31,409
Fair Value		31,513
Gross Unrealized Gains		$ 104