Note 6 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

	September 30, 2014
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	539,919	$	198	$	29	$	540,088
Mortgage-backed securities		703,312		1,085		21,073		683,324
Collateralized mortgage obligations		80		-		34		46
Corporate debt securities		94,941		751		1,355		94,337
Mutual funds		6,000		-		183		5,817
Preferred stock of government sponsored entities		7,196		2,056		-		9,252
Other equity securities		3,608		3,620		-		7,228
Total	$	1,355,056	$	7,710	$	22,674	$	1,340,092

	December 31, 2013
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		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	$	1,637,965	$	18,511	$	69,808	$	1,586,668

Investments Classified by Contractual Maturity Date [Table Text Block]

	Securities Available-For-Sale
	Amortized cost		Fair value
	(In thousands)
Due in one year or less	$	115,047	$	115,156
Due after one year through five years		446,739		447,662
Due after five years through ten years		85,693		84,983
Due after ten years (1)		707,577		692,291
Total	$	1,355,056	$	1,340,092
(1) Equity securities are reported in this category

Schedule of Unrealized Loss on Investments [Table Text Block]

	September 30, 2014
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(Dollars in thousands)
Securities Available-for-Sale
U.S. treasury securities	$	174,959	$	29	$	-	$	-	$	174,959	$	29
Mortgage-backed securities		92,436		151		551,854		20,922		644,290		21,073
Collateralized mortgage obligations		-		-		46		34		46		34
Corporate debt securities		-		-		63,645		1,355		63,645		1,355
Mutual funds		-		-		5,817		183		5,817		183
Total	$	267,395	$	180	$	621,362	$	22,494	$	888,757	$	22,674

	December 31, 2013
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		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