Investments

Investments available for sale consist of the following:



March 31, 2019 (In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Treasury securities	$	288,897	$	1,377	$	(3,431	)	$	286,843
U.S. agency securities	33,638		—		(451		)	33,187
U.S. agency mortgage-backed securities	675,268		5,601		(8,727		)	672,142
Municipal debt securities(1)	447,538		14,172		(328		)	461,382
Non-U.S. government securities	45,034		1,332		—			46,366
Corporate debt securities(2)	759,846		7,690		(4,135		)	763,401
Residential and commercial mortgage securities	185,393		2,579		(762		)	187,210
Asset-backed securities	316,759		488		(2,511		)	314,736
Money market funds	210,821		1		—			210,822
Total investments available for sale	$	2,963,194	$	33,240	$	(20,345	)	$	2,976,089



December 31, 2018 (In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Treasury securities	$	295,145	$	693	$	(5,946	)	$	289,892
U.S. agency securities	33,645		—		(648		)	32,997
U.S. agency mortgage-backed securities	649,228		2,520		(14,570		)	637,178
Municipal debt securities(1)	481,547		5,351		(3,019		)	483,879
Non-U.S. government securities	44,999		285		(283		)	45,001
Corporate debt securities(2)	738,964		1,005		(14,768		)	725,201
Residential and commercial mortgage securities	122,369		686		(1,217		)	121,838
Asset-backed securities	288,371		305		(3,679		)	284,997
Money market funds	139,082		1		—			139,083
Total investments available for sale	$	2,793,350	$	10,846	$	(44,130	)	$	2,760,066



	March 31,		December 31,
(1) The following table summarizes municipal debt securities as of :	2019		2018
Special revenue bonds	68.9	%	69.0	%
General obligation bonds	25.8		26.0
Certificate of participation bonds	3.8		3.6
Tax allocation bonds	1.0		0.9
Special tax bonds	0.5		0.5
Total	100.0	%	100.0	%



	March 31,		December 31,
(2) The following table summarizes corporate debt securities as of :	2019		2018
Financial	36.1	%	37.1	%
Consumer, non-cyclical	21.9		20.7
Communications	11.8		12.6
Consumer, cyclical	7.6		7.6
Energy	5.5		5.7
Industrial	5.0		4.7
Utilities	4.9		5.0
Technology	3.9		3.1
Basic materials	3.3		3.5
Total	100.0	%	100.0	%

The amortized cost and fair value of investments available for sale at March 31, 2019, by contractual maturity, are shown below. 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 U.S. agency mortgage-backed securities, residential and commercial mortgage securities and asset-backed securities provide for periodic payments throughout their lives, they are listed below in separate categories.



(In thousands)	Amortized Cost		Fair Value
U.S. Treasury securities:
Due in 1 year	$	9,992	$	9,932
Due after 1 but within 5 years	179,482		179,829
Due after 5 but within 10 years	99,423		97,082
Subtotal	288,897		286,843
U.S. agency securities:
Due in 1 year	—		—
Due after 1 but within 5 years	33,638		33,187
Subtotal	33,638		33,187
Municipal debt securities:
Due in 1 year	4,246		4,251
Due after 1 but within 5 years	85,262		85,920
Due after 5 but within 10 years	184,082		190,665
Due after 10 years	173,948		180,546
Subtotal	447,538		461,382
Non-U.S. government securities:
Due in 1 year	—		—
Due after 1 but within 5 years	19,804		20,275
Due after 5 but within 10 years	25,230		26,091
Subtotal	45,034		46,366
Corporate debt securities:
Due in 1 year	82,329		82,043
Due after 1 but within 5 years	421,500		422,725
Due after 5 but within 10 years	254,780		257,349
Due after 10 years	1,237		1,284
Subtotal	759,846		763,401
U.S. agency mortgage-backed securities	675,268		672,142
Residential and commercial mortgage securities	185,393		187,210
Asset-backed securities	316,759		314,736
Money market funds	210,821		210,822
Total investments available for sale	$	2,963,194	$	2,976,089

Gross gains and losses realized on the sale of investments available for sale were as follows:



	Three Months Ended March 31,
(In thousands)	2019		2018
Realized gross gains	$	671	$	791
Realized gross losses	11		594

The fair value of investments available for sale in an unrealized loss position and the related unrealized losses were as follows:



	Less than 12 months					12 months or more					Total
March 31, 2019 (In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. Treasury securities	$	—	$	—		$	185,624	$	(3,431	)	$	185,624	$	(3,431	)
U.S. agency securities	—		—			33,187		(451		)	33,187		(451		)
U.S. agency mortgage-backed securities	34,343		(102		)	361,212		(8,625		)	395,555		(8,727		)
Municipal debt securities	539		—			47,265		(328		)	47,804		(328		)
Corporate debt securities	17,581		(46		)	371,460		(4,089		)	389,041		(4,135		)
Residential and commercial mortgage securities	43,743		(463		)	12,345		(299		)	56,088		(762		)
Asset-backed securities	191,697		(1,910		)	51,473		(601		)	243,170		(2,511		)
Total	$	287,903	$	(2,521	)	$	1,062,566	$	(17,824	)	$	1,350,469	$	(20,345	)



	Less than 12 months					12 months or more					Total
December 31, 2018 (In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. Treasury securities	$	45,505	$	(215	)	$	165,015	$	(5,731	)	$	210,520	$	(5,946	)
U.S. agency securities	—		—			32,997		(648		)	32,997		(648		)
U.S. agency mortgage-backed securities	106,177		(1,070		)	341,579		(13,500		)	447,756		(14,570		)
Municipal debt securities	114,442		(1,176		)	104,930		(1,843		)	219,372		(3,019		)
Non-U.S. government securities	13,497		(283		)	—		—			13,497		(283		)
Corporate debt securities	381,912		(7,538		)	231,124		(7,230		)	613,036		(14,768		)
Residential and commercial mortgage securities	51,477		(650		)	13,321		(567		)	64,798		(1,217		)
Asset-backed securities	217,546		(3,165		)	29,852		(514		)	247,398		(3,679		)
Total	$	930,556	$	(14,097	)	$	918,818	$	(30,033	)	$	1,849,374	$	(44,130	)

The gross unrealized losses on these investment securities are principally associated with the changes in market interest rates as well as changes in credit spreads subsequent to their purchase. Each issuer is current on its scheduled interest and principal payments. We assess our intent to sell these securities and whether we will be required to sell these securities before the recovery of their amortized cost basis when determining whether an impairment is other-than-temporary. There were no other-than-temporary impairments in each of the three months ended March 31, 2019 and 2018.

The Company's other invested assets at March 31, 2019 and December 31, 2018 totaled $32.7 million and $31.0 million, respectively. Other invested assets are comprised of limited partnership interests which are accounted for under the equity method of accounting with changes in value reported in other income. Due to the timing of receiving financial information from these partnerships, the results are generally reported on a one month or quarter lag.

The fair value of investments deposited with insurance regulatory authorities to meet statutory requirements was $9.2 million at March 31, 2019 and $8.9 million at December 31, 2018. In connection with its insurance and reinsurance activities, Essent Re is required to maintain assets in trusts for the benefit of its contractual counterparties. The fair value of the investments on deposit in these trusts was $871.8 million at March 31, 2019 and $759.9 million at December 31, 2018. In connection with excess of loss reinsurance agreements (see Note 4), Essent Guaranty is required to maintain assets on deposit for the benefit of the reinsurers. The fair value of the assets on deposit was $6.8 million at March 31, 2019 and $3.4 million at December 31, 2018. Essent Guaranty is also required to maintain assets on deposit for the benefit of the sponsor of a fixed income investment commitment. The fair value of the assets on deposit was $6.3 million at March 31, 2019 and $6.3 million at December 31, 2018.

Net investment income consists of:



	Three Months Ended March 31,
(In thousands)	2019			2018
Fixed maturities	$	19,743		$	13,643
Short-term investments	1,058			751
Gross investment income	20,801			14,394
Investment expenses	(921		)	(680		)
Net investment income	$	19,880		$	13,714