INVESTMENT SECURITIES

The following table presents the amortized cost and fair value of the investment securities portfolio as of the dates indicated:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
September 30, 2017
Securities available-for-sale:
SBA loan pool securities	$	1,056	$	9	$	—		$	1,065
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	503,193		20		(14,096		)	489,117
Non-agency residential mortgage-backed securities	844		16		(1		)	859
Non-agency commercial mortgage-backed securities	305,360		5,737		(180		)	310,917
Collateralized loan obligations	1,808,126		11,429		(364		)	1,819,191
Corporate debt securities	123,718		10,797		—			134,515
Total securities available-for-sale	$	2,742,297	$	28,008	$	(14,641	)	$	2,755,664
December 31, 2016
Securities held-to-maturity:
Non-agency commercial mortgage-backed securities	$	305,918	$	2,949	$	(1,781	)	$	307,086
Collateralized loan obligations	338,226		1,461		(61		)	339,626
Corporate debt securities	240,090		13,032		(91		)	253,031
Total securities held-to-maturity	$	884,234	$	17,442	$	(1,933	)	$	899,743
Securities available-for-sale:
SBA loan pool securities	$	1,221	$	—	$	—		$	1,221
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	830,682		9		(23,418		)	807,273
Non-agency residential mortgage-backed securities	121,397		18		(4,238		)	117,177
Collateralized loan obligations	1,395,094		12,449		(674		)	1,406,869
Corporate debt securities	48,574		482		(108		)	48,948
Total securities available-for-sale	$	2,396,968	$	12,958	$	(28,438	)	$	2,381,488

During the three months ended June 30, 2017, the Company evaluated its securities held-to-maturity and determined that certain securities no longer adhere to the Company’s strategic focus and could be sold or reinvested to potentially improve the Company’s liquidity position or duration profile. Accordingly, the Company was no longer able to assert that it had the intent to hold these securities until maturity. As a result, the Company transferred all $740.9 million of its securities held-to-maturity to securities available-for-sale, which resulted in a pre-tax increase to accumulated other comprehensive income of $22.0 million as of June 30, 2017. Due to the transfer, the Company’s ability to assert that it has the intent and ability to hold to maturity debt securities will be limited for the foreseeable future.

The following table presents amortized cost and fair value of the available-for-sale investment securities portfolio by expected maturity. In the case of mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities, expected maturities may differ from contractual maturities because borrowers generally have the right to call or prepay obligations with or without call or prepayment penalties. For that reason, mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities are not included in the maturity categories.



	September 30, 2017
	Amortized Cost		Fair Value
	(In thousands)
Maturity:
Within one year	$	—	$	—
One to five years	—		—
Five to ten years	120,718		131,181
Greater than ten years	3,000		3,334
Collateralized loan obligations, SBA loan pool securities, and mortgage-backed securities	2,618,579		2,621,149
Total	$	2,742,297	$	2,755,664

At September 30, 2017 and December 31, 2016, there were no holdings of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10 percent of the Company's stockholders’ equity.

The following table presents proceeds from sales and calls of securities available-for-sale and the associated gross gains and losses realized through earnings upon the sales and calls of securities available-for-sale for the periods indicated:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
	(In thousands)
Gross realized gains on sales and calls of securities available-for-sale	$	7,625	$	487	$	12,080	$	30,105
Gross realized losses on sales and calls of securities available-for-sale	—		—		—		(5		)
Net realized gains on sales and calls of securities available-for-sale	$	7,625	$	487	$	12,080	$	30,100
Proceeds from sales and calls of securities available-for-sale	$	312,961	$	232,512	$	1,199,551	$	3,783,965
Tax expense on sales and calls of securities available-for-sale	$	3,171	$	202	$	5,024	$	12,507

Investment securities with carrying values of $719.0 million and $581.8 million as of September 30, 2017 and December 31, 2016, respectively, were pledged to secure FHLB advances, public deposits, repurchase agreements, and for other purposes as required or permitted by law.

The following table summarizes the investment securities with unrealized losses by security type and length of time in a continuous unrealized loss position as of the dates indicated:



	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In thousands)
September 30, 2017
Securities available-for-sale:
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	$	119,103	$	(2,436	)	$	366,014	$	(11,660	)	$	485,117	$	(14,096	)
Non-agency residential mortgage-backed securities	—		—			209		(1		)	209		(1		)
Non-agency commercial mortgage-backed securities	21,771		(180		)	—		—			21,771		(180		)
Collateralized loan obligations	204,197		(354		)	10,962		(10		)	215,159		(364		)
Total securities available-for-sale	$	345,071	$	(2,970	)	$	377,185	$	(11,671	)	$	722,256	$	(14,641	)
December 31, 2016
Securities held-to-maturity:
Non-agency commercial mortgage-backed securities	$	60,221	$	(1,781	)	$	—	$	—		$	60,221	$	(1,781	)
Collateralized loan obligation	10,056		(6		)	56,095		(55		)	66,151		(61		)
Corporate debt securities	9,907		(91		)	—		—			9,907		(91		)
Total securities held-to-maturity	$	80,184	$	(1,878	)	$	56,095	$	(55	)	$	136,279	$	(1,933	)
Securities available-for-sale:
SBA loan pool securities	$	1,221	$	—		$	—	$	—		$	1,221	$	—
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	805,803		(23,410		)	760		(8		)	806,563		(23,418		)
Non-agency residential mortgage-backed securities	116,216		(4,238		)	230		—			116,446		(4,238		)
Collateralized loan obligations	187,592		(674		)	—		—			187,592		(674		)
Corporate debt securities	—		—			3,530		(108		)	3,530		(108		)
Total securities available-for-sale	$	1,110,832	$	(28,322	)	$	4,520	$	(116	)	$	1,115,352	$	(28,438	)

The Company did not record OTTI for investment securities for the three and nine months ended September 30, 2017 or 2016. At September 30, 2017, the Company’s securities available-for-sale portfolio consisted of 205 securities, 44 of which were in an unrealized loss position. At December 31, 2016, the Company’s securities available-for-sale portfolio consisted of 161 securities, 59 of which were in an unrealized loss position and securities held-to-maturity consisted of 87 securities, 15 of which were in an unrealized loss position.

The Company monitors its securities portfolio to ensure it has adequate credit support. As of September 30, 2017, the Company believed there was no OTTI and did not have the intent to sell these securities and, for securities with fair value below amortized cost at September 30, 2017, it is not likely that it will be required to sell the securities before their anticipated recovery. The Company considers the lowest credit rating for identification of potential OTTI. As of September 30, 2017, all of the Company's investment securities in an unrealized loss position received an investment grade credit rating.