Investments

The amortized cost, gross unrealized gains and losses and fair value of the investment portfolio at September 30, 2017 and December 31, 2016 are shown below.



September 30, 2017
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	104,168	$	331	$	(799	)	$	103,700
Obligations of U.S. states and political subdivisions	2,069,592		50,505		(6,814		)	2,113,283
Corporate debt securities	1,865,640		16,151		(6,536		)	1,875,255
ABS	9,857		3		—			9,860
RMBS	198,756		113		(5,973		)	192,896
CMBS	308,735		1,517		(4,827		)	305,425
CLOs	109,417		446		(129		)	109,734
Total debt securities	4,666,165		69,066		(25,078		)	4,710,153
Equity securities	7,202		50		(13		)	7,239
Total investment portfolio	$	4,673,367	$	69,116	$	(25,091	)	$	4,717,392



December 31, 2016
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses ⁽¹⁾			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	73,847	$	407	$	(724	)	$	73,530
Obligations of U.S. states and political subdivisions	2,147,458		20,983		(25,425		)	2,143,016
Corporate debt securities	1,756,461		6,059		(18,610		)	1,743,910
ABS	59,519		74		(28		)	59,565
RMBS	231,733		102		(7,626		)	224,209
CMBS	327,042		769		(7,994		)	319,817
CLOs	121,151		226		(202		)	121,175
Total debt securities	4,717,211		28,620		(60,609		)	4,685,222
Equity securities	7,144		8		(24		)	7,128
Total investment portfolio	$	4,724,355	$	28,628	$	(60,633	)	$	4,692,350


⁽¹⁾	At September 30, 2017 and December 31, 2016, there were no other-than-temporary impairment losses recorded in other comprehensive income.

The FHLB Advance is secured by eligible collateral whose fair value must be maintained at 102% of the outstanding principal balance. As of September 30, 2017, that collateral is included in our total investment portfolio amount with a total fair value of $167.2 million.

The amortized cost and fair values of debt securities at September 30, 2017, by contractual maturity, are shown in the following table. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Because most asset-backed and mortgage-backed securities and collateralized loan obligations provide for periodic payments throughout their lives, they are listed in separate categories.



September 30, 2017
(In thousands)	Amortized Cost		Fair Value
Due in one year or less	$	439,771	$	440,227
Due after one year through five years	1,333,112		1,342,110
Due after five years through ten years	972,932		980,813
Due after ten years	1,293,585		1,329,088
	$	4,039,400	$	4,092,238

ABS	9,857		9,860
RMBS	198,756		192,896
CMBS	308,735		305,425
CLOs	109,417		109,734
Total as of September 30, 2017	$	4,666,165	$	4,710,153

At September 30, 2017 and December 31, 2016, the investment portfolio had gross unrealized losses of $25.1 million and $60.6 million, respectively. For those securities in an unrealized loss position, the length of time the securities were in such a position, as measured by their month-end fair values, is as follows:



September 30, 2017	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	74,136	$	(524	)	$	22,423	$	(275	)	$	96,559	$	(799	)
Obligations of U.S. states and political subdivisions	411,460		(4,520		)	85,700		(2,294		)	497,160		(6,814		)
Corporate debt securities	434,056		(4,367		)	75,592		(2,169		)	509,648		(6,536		)
ABS	2,613		—			—		—			2,613		—
RMBS	37,676		(713		)	148,748		(5,260		)	186,424		(5,973		)
CMBS	126,709		(2,375		)	57,189		(2,452		)	183,898		(4,827		)
CLOs	7,276		(129		)	—		—			7,276		(129		)
Equity securities	381		(5		)	171		(8		)	552		(13		)
Total	$	1,094,307	$	(12,633	)	$	389,823	$	(12,458	)	$	1,484,130	$	(25,091	)



December 31, 2016	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	48,642	$	(724	)	$	—	$	—		$	48,642	$	(724	)
Obligations of U.S. states and political subdivisions	1,136,676		(24,918		)	13,681		(507		)	1,150,357		(25,425		)
Corporate debt securities	915,777		(16,771		)	35,769		(1,839		)	951,546		(18,610		)
ABS	3,366		(28		)	656		—			4,022		(28		)
RMBS	46,493		(857		)	171,326		(6,769		)	217,819		(7,626		)
CMBS	205,545		(7,529		)	38,587		(465		)	244,132		(7,994		)
CLOs	13,278		(73		)	34,760		(129		)	48,038		(202		)
Equity securities	568		(15		)	137		(9		)	705		(24		)
Total	$	2,370,345	$	(50,915	)	$	294,916	$	(9,718	)	$	2,665,261	$	(60,633	)

The unrealized losses in all categories of our investments at September 30, 2017 and December 31, 2016 were primarily caused by changes in interest rates between the time of purchase and the respective fair value measurement date. There were 343 and 607 securities in an unrealized loss position at September 30, 2017 and December 31, 2016, respectively.

During each of the three and nine months ended September 30, 2017 and 2016 there were no other-than-temporary impairments (“OTTI”) recognized. The net realized investment gains (losses) on the investment portfolio were as follows:



	Three Months Ended September 30,					Nine Months Ended September 30,
(In thousands)	2017			2016		2017			2016
Fixed maturities	$	(50	)	$	1,511	$	(227	)	$	5,397
Equity securities	3			3,581		16			3,587
Net realized investments (losses) gains	$	(47	)	$	5,092	$	(211	)	$	8,984



	Three Months Ended September 30,						Nine Months Ended September 30,
(In thousands)	2017			2016			2017			2016
Gains on sales	$	32		$	6,168		$	861		$	11,677
Losses on sales	(79		)	(1,076		)	(1,072		)	(2,693		)
Net realized investments (losses) gains	$	(47	)	$	5,092		$	(211	)	$	8,984