Note 3 - Investment Securities Available for Sale (Details) - Available-for-Sale Securities (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Agency ARMs
Amortized Cost	$ 893,068		$ 940,007
Unrealized Gains	32,322		17,219
Unrealized Losses	(33,139)		(44,783)
Fair Value	892,251		912,443
Freddie Mac [Member] | Agency ARMs [Member]
Agency ARMs
Amortized Cost	60,536		67,121
Unrealized Gains	60		37
Unrealized Losses	(1,019)		(2,101)
Fair Value	59,577		65,057
Freddie Mac [Member] | Agency Fixed Rate [Member]
Agency ARMs
Amortized Cost	39,140		43,920
Unrealized Losses	(1,018)		(1,714)
Fair Value	38,122		42,206
Freddie Mac [Member] | Agency IOs [Member]
Agency ARMs
Amortized Cost	40,922	[1]	43,468	[1]
Unrealized Gains	254	[1]	252	[1]
Unrealized Losses	(5,168)	[1]	(5,187)	[1]
Fair Value	36,008	[1]	38,533	[1]
Fannie Mae [Member] | Agency ARMs [Member]
Agency ARMs
Amortized Cost	117,082		130,487
Unrealized Gains	41		58
Unrealized Losses	(1,948)		(3,128)
Fair Value	115,175		127,417
Fannie Mae [Member] | Agency Fixed Rate [Member]
Agency ARMs
Amortized Cost	467,546		518,598
Unrealized Losses	(15,177)		(24,861)
Fair Value	452,369		493,737
Fannie Mae [Member] | Agency IOs [Member]
Agency ARMs
Amortized Cost	56,402	[1]	60,813	[1]
Unrealized Gains	1,152	[1]	1,300	[1]
Unrealized Losses	(4,462)	[1]	(5,007)	[1]
Fair Value	53,092	[1]	57,106	[1]
Ginnie Mae [Member] | Agency ARMs [Member]
Agency ARMs
Amortized Cost	13,571		17,049
Unrealized Losses	(202)		(201)
Fair Value	13,369		16,848
Ginnie Mae [Member] | Agency IOs [Member]
Agency ARMs
Amortized Cost	45,071	[1]	37,660	[1]
Unrealized Gains	332	[1]	706	[1]
Unrealized Losses	(3,978)	[1]	(2,396)	[1]
Fair Value	41,425	[1]	35,970	[1]
CMBS [Member] | Investment Held in Securitization Trust [Member]
Agency ARMs
Amortized Cost	25,627	[2]	74,314	[2]
Unrealized Gains	12,752	[2]	18,264	[2]
Unrealized Losses		[2]		[2]
Fair Value	38,379	[2]	92,578	[2]
CMBS [Member]
Agency ARMs
Amortized Cost	28,787
Unrealized Gains	17,166
Fair Value	45,953
Agency ARMs [Member]
Agency ARMs
Amortized Cost	191,189		214,657
Unrealized Gains	101		95
Unrealized Losses	(3,169)		(5,430)
Fair Value	188,121		209,322
Agency Fixed Rate [Member]
Agency ARMs
Amortized Cost	506,686		562,518
Unrealized Losses	(16,195)		(26,575)
Fair Value	490,491		535,943
Agency IOs [Member]
Agency ARMs
Amortized Cost	142,395	[1]	141,941	[1]
Unrealized Gains	1,738	[1]	2,258	[1]
Unrealized Losses	(13,608)	[1]	(12,590)	[1]
Fair Value	130,525	[1]	131,609	[1]
Agency RMBs [Member]
Agency ARMs
Amortized Cost	840,270		919,116
Unrealized Gains	1,839		2,353
Unrealized Losses	(32,972)		(44,595)
Fair Value	809,137		876,874
Non-Agency RMBS [Member]
Agency ARMs
Amortized Cost	2,145		2,413
Unrealized Gains	62		136
Unrealized Losses	(167)		(188)
Fair Value	2,040		2,361
Collateralized Loan Obligation [Member]
Agency ARMs
Amortized Cost	21,866		18,478
Unrealized Gains	13,255		14,730
Fair Value	35,121		33,208
Investment Held in Securitization Trust [Member]
Agency ARMs
Amortized Cost	25,627		74,314
Unrealized Gains	12,752		18,264
Fair Value	$ 38,379		$ 92,578

[1] Included in investment securities available for sale are Agency IOs. Agency IOs are measured at fair value through earnings.

[2] CMBS investments have contractual maturities ranging from 0 to 10 years.