Note 4 - Investment Securities (Details) - Temporarily Impaired Securities (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	30
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	19
US Treasury Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	$ 75,064	$ 49,969
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	1	5
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	1	1
Securities Available-for-Sale - Fair Value	75,064	49,969
Securities Available-for-Sale - Unrealized Losses	1	5
Securities Available-for-Sale - No. of Issuances	1	1
Collateralized Mortgage Backed Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	792,012	231
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	64,526	1
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	25	2
Securities Available-for-Sale - 12 Months or longer - Fair Value	272	170
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	2	1
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	7	6
Securities Available-for-Sale - Fair Value	792,284	401
Securities Available-for-Sale - Unrealized Losses	64,528	2
Securities Available-for-Sale - No. of Issuances	32	8
Mortgage Backed Securities Non Agency Member
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	94
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	1
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	1
Securities Available-for-Sale - 12 Months or longer - Fair Value		96
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses		2
Securities Available-for-Sale - 12 Months or longer - No. of Issuances		1
Securities Available-for-Sale - Fair Value	94	96
Securities Available-for-Sale - Unrealized Losses	1	2
Securities Available-for-Sale - No. of Issuances	1	1
Collateralized Mortgage Obligations [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	68
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	4
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	2
Securities Available-for-Sale - 12 Months or longer - Fair Value	301	439
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	50	35
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	3	4
Securities Available-for-Sale - Fair Value	369	439
Securities Available-for-Sale - Unrealized Losses	54	35
Securities Available-for-Sale - No. of Issuances	5	4
Corporate Debt Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	9,970	52,468
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	30	2,532
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	1	4
Securities Available-for-Sale - 12 Months or longer - Fair Value	100,081	253,430
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	4,919	11,570
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	8	22
Securities Available-for-Sale - Fair Value	110,051	305,898
Securities Available-for-Sale - Unrealized Losses	4,949	14,102
Securities Available-for-Sale - No. of Issuances	9	26
Mutual Funds Member
Securities Available-for-Sale
Securities Available-for-Sale - 12 Months or longer - Fair Value	5,724
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	275
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	1
Securities Available-for-Sale - Fair Value	5,724
Securities Available-for-Sale - Unrealized Losses	275
Securities Available-for-Sale - No. of Issuances	1
Total [Member]
Securities Available-for-Sale
Securities Available-for-Sale - Less than 12 Months - Fair Value	877,208	102,668
Securities Available-for-Sale - Less than 12 Months - Unrealized Losses	64,562	2,538
Securities Available-for-Sale - Less than 12 Months - No. of Issuances	30	7
Securities Available-for-Sale - 12 Months or longer - Fair Value	106,378	254,276
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses	5,246	11,612
Securities Available-for-Sale - 12 Months or longer - No. of Issuances	19	34
Securities Available-for-Sale - Fair Value	983,586	356,944
Securities Available-for-Sale - Unrealized Losses	69,808	14,150
Securities Available-for-Sale - No. of Issuances	49	41
Asset-backed Securities [Member]
Securities Available-for-Sale
Securities Available-for-Sale - 12 Months or longer - Fair Value		141
Securities Available-for-Sale - 12 Months or longer - Unrealized Losses		4
Securities Available-for-Sale - 12 Months or longer - No. of Issuances		1
Securities Available-for-Sale - Fair Value		141
Securities Available-for-Sale - Unrealized Losses		$ 4
Securities Available-for-Sale - No. of Issuances		1