Note 6 - Investment Securities (Tables)

6 Months Ended

Jun. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Cost Gross Unrealized Gains Gross Unrealized Losses and Fair Values of Investment [Table text Block]

	June 30, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	565,091	$	73	$	1	$	565,163
Mortgage-backed securities		680,556		1,210		24,897		656,869
Collateralized mortgage obligations		81		-		35		46
Corporate debt securities		94,938		848		1,449		94,337
Mutual funds		6,000		-		167		5,833
Preferred stock of government sponsored entities		4,611		6,885		1		11,495
Other equity securities		3,608		2,638		-		6,246
Total securities available-for-sale	$	1,354,885	$	11,654	$	26,550	$	1,339,989
Total investment securities	$	1,354,885	$	11,654	$	26,550	$	1,339,989

	December 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	460,095	$	99	$	1	$	460,193
Mortgage-backed securities		1,010,294		7,049		64,529		952,814
Collateralized mortgage obligations		5,929		231		54		6,106
Asset-backed securities		123		-		-		123
Corporate debt securities		154,955		298		4,949		150,304
Mutual funds		6,000		-		275		5,725
Preferred stock of government sponsored entities		569		10,834		-		11,403
Total securities available-for-sale	$	1,637,965	$	18,511	$	69,808	$	1,586,668
Total investment securities	$	1,637,965	$	18,511	$	69,808	$	1,586,668

Schedule of Amortized Cost and Fair Value of Investment Securities by Contractual Maturities [Table Text Block]

	Securities available-for-sale
	Amortized cost		Fair value
	(In thousands)
Due in one year or less	$	450,032	$	450,048
Due after one year through five years		138,285		139,329
Due after five years through ten years		85,857		85,165
Due after ten years (1)		680,711		665,447
Total	$	1,354,885	$	1,339,989
(1) Equity securities are reported in this category

Fair Value, Unrealized Losses, and Number of Issuances of the Temporarily Impaired Securities [Table Text Block]

	June 30, 2014
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(Dollars in thousands)
Securities Available-for-Sale
U.S. treasury securities	$	99,999	$	1	$	-	$	-	$	99,999	$	1
Mortgage-backed securities		185		1		636,390		24,896		636,575		24,897
Collateralized mortgage obligations		-		-		46		35		46		35
Corporate debt securities		-		-		63,551		1,449		63,551		1,449
Mutual funds		-		-		5,833		167		5,833		167
Preferred stock of government sponsored entities		970		1		-		-		970		1
Total securities available-for-sale	$	101,154	$	3	$	705,820	$	26,547	$	806,974	$	26,550
Total investment securities	$	101,154	$	3	$	705,820	$	26,547	$	806,974	$	26,550

	December 31, 2013
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(Dollars in thousands)
Securities Available-for-Sale
U.S. treasury securities	$	75,064	$	1	$	-	$	-	$	75,064	$	1
Mortgage-backed securities		792,012		64,526		272		2		792,284		64,528
Mortgage-backed securities-Non-agency		94		1		-		-		94		1
Collateralized mortgage obligations		68		4		301		50		369		54
Corporate debt securities		9,970		30		100,081		4,919		110,051		4,949
Mutual funds		-		-		5,724		275		5,724		275
Total securities available-for-sale	$	877,208	$	64,562	$	106,378	$	5,246	$	983,586	$	69,808
Total investment securities	$	877,208	$	64,562	$	106,378	$	5,246	$	983,586	$	69,808