The amortized cost, gross unrealized gains and losses, and fair value of investments in fixed income securities classified as available-for-sale at June 30, 2019 and December 31, 2018 are shown in tables 7.1a and 7.1b below.



Details of fixed income securities by category as of June 30, 2019
Table	7.1a
(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		$	194,222	$	1,474	$	(127	)	$	195,569
Obligations of U.S. states and political subdivisions		1,566,166		88,379		(648		)	1,653,897
Corporate debt securities		2,570,289		61,459		(3,134		)	2,628,614
Asset backed securities (“ABS”)		215,016		2,787		(102		)	217,701
Residential mortgage backed securities (“RMBS”)		213,024		183		(4,710		)	208,497
Commercial mortgage backed securities (“CMBS”)		268,189		4,450		(750		)	271,889
Collateralized loan obligations (“CLO”)		330,530		55		(1,929		)	328,656
Total fixed income securities		$	5,357,436	$	158,787	$	(11,400	)	$	5,504,823



Details of fixed income securities by category as of December 31, 2018
Table	7.1b
(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		$	167,655	$	597	$	(1,076	)	$	167,176
Obligations of U.S. states and political subdivisions		1,701,826		29,259		(10,985		)	1,720,100
Corporate debt securities		2,439,173		2,103		(40,514		)	2,400,762
ABS		111,953		226		(146		)	112,033
RMBS		189,238		32		(10,309		)	178,961
CMBS		276,352		888		(9,580		)	267,660
CLOs		310,587		2		(5,294		)	305,295
Total fixed income securities		$	5,196,784	$	33,107	$	(77,904	)	$	5,151,987

We had $13.7 million and $13.5 million of investments at fair value on deposit with various states as of June 30, 2019 and December 31, 2018, respectively, due to regulatory requirements of those state insurance departments.

The amortized cost and fair values of fixed income securities at June 30, 2019, by contractual maturity, are shown in table 7.2 below. Actual 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 ABS, RMBS, CMBS, and CLOs provide for periodic payments throughout their lives, they are listed in separate categories.



Fixed income securities maturity schedule
Table	7.2
		June 30, 2019
(In thousands)		Amortized cost		Fair Value
Due in one year or less		$	367,161	$	367,474
Due after one year through five years		1,900,096		1,930,664
Due after five years through ten years		930,951		976,031
Due after ten years		1,132,469		1,203,911
		4,330,677		4,478,080

ABS		215,016		217,701
RMBS		213,024		208,497
CMBS		268,189		271,889
CLOs		330,530		328,656
Total as of June 30, 2019		$	5,357,436	$	5,504,823

Proceeds from sales of fixed income securities classified as available-for-sale were $183.6 million and $25.1 million during the six months ended June 30, 2019 and 2018, respectively. Gross gains of $1.2 million and $2.0 million and gross losses of $1.1 million and $2.3 million were realized on those sales during the three and six months ended June 30, 2019, respectively. Gross gains of $0.1 million and $0.2 million and gross losses of $0.6 million and $1.0 million were realized on those sales during the three and six months ended June 30, 2018, respectively. During the six months ended June 30, 2019, we recorded other-than-temporary impairment (“OTTI”) losses of $0.1 million. During the three and six months ended June 30, 2018, we recorded OTTI losses of $1.3 million.



Details of equity security investments as of June 30, 2019
Table	7.3a
(In thousands)		Cost		Gross Gains		Gross Losses			Fair Value
Equity securities		$	3,991	$	129	$	(6	)	$	4,114



Details of equity security investments as of December 31, 2018
Table	7.3b
(In thousands)		Cost		Gross Gains		Gross Losses			Fair Value
Equity securities		$	3,993	$	11	$	(72	)	$	3,932

For the three and six months ended June 30, 2019, we recognized $0.1 million and $0.2 million of net gains on equity securities still held as of June 30, 2019. For the six months ended June 30, 2018, we recognized $0.1 million of net losses on equity securities still held as of June 30, 2018.

Other invested assets include an investment in Federal Home Loan Bank (“FHLB”) stock that is carried at cost, which due to its nature approximates fair value. Ownership of FHLB stock provides access to a secured lending facility, and our current FHLB Advance amount is secured by eligible collateral whose fair value is maintained at a minimum of 102% of the outstanding principal balance. As of June 30, 2019, that collateral consisted of fixed income securities included in our total investment portfolio, and cash and cash equivalents, with a total fair value of $163.0 million.

Tables 7.4a and 7.4b below summarize, for all available-for-sale investments in an unrealized loss position at June 30, 2019 and December 31, 2018, the aggregate fair value and gross unrealized loss by the length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in tables 7.4a and 7.4b are estimated using the process described in Note 8 - “Fair Value Measurements” to these consolidated financial statements and in Note 3 - “Significant Accounting Policies” of the notes to the consolidated financial statements in our 2018 Annual Report on Form 10-K.



Unrealized loss aging for securities by type and length of time as of June 30, 2019
Table	7.4a
		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		$	12,483	$	(19	)	$	45,423	$	(108	)	$	57,906	$	(127	)
Obligations of U.S. states and political subdivisions		2,283		(468		)	57,193		(180		)	59,476		(648		)
Corporate debt securities		29,333		(1,987		)	298,419		(1,147		)	327,752		(3,134		)
ABS		9,257		(102		)	—		—			9,257		(102		)
RMBS		32,181		(297		)	158,325		(4,413		)	190,506		(4,710		)
CMBS		—		—			78,697		(750		)	78,697		(750		)
CLOs		247,983		(1,587		)	45,137		(342		)	293,120		(1,929		)
Total		$	333,520	$	(4,460	)	$	683,194	$	(6,940	)	$	1,016,714	$	(11,400	)



Unrealized loss aging for securities by type and length of time as of December 31, 2018
Table	7.4b
		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		$	23,710	$	(15	)	$	69,146	$	(1,061	)	$	92,856	$	(1,076	)
Obligations of U.S. states and political subdivisions		316,655		(3,875		)	358,086		(7,110		)	674,741		(10,985		)
Corporate debt securities		1,272,279		(18,130		)	785,627		(22,384		)	2,057,906		(40,514		)
ABS		51,324		(146		)	—		—			51,324		(146		)
RMBS		24		—			178,573		(10,309		)	178,597		(10,309		)
CMBS		65,704		(1,060		)	163,272		(8,520		)	228,976		(9,580		)
CLOs		296,497		(5,294		)	—		—			296,497		(5,294		)
Total		$	2,026,193	$	(28,520	)	$	1,554,704	$	(49,384	)	$	3,580,897	$	(77,904	)