Investments

In the first quarter of 2018, we adopted ASU 2016-01, which resulted in changes in the fair value of equity securities still held at March 31, 2018, being reported in net income (loss) instead of being reported in other comprehensive income (loss). See Note 1, Accounting Policies, for additional discussion.

The following table provides cost or amortized cost, gross unrealized gains, gross unrealized losses and fair value for our fixed-maturity and equity securities:



(Dollars in millions)	Cost or amortized cost		Gross unrealized				Fair value
At March 31, 2018	Cost or amortized cost		gains		losses		Fair value
Fixed maturity securities:
Corporate	$	5,452	$	155	$	35	$	5,572
States, municipalities and political subdivisions	4,304		85		35		4,354
Commercial mortgage-backed	285		3		2		286
Government-sponsored enterprises	277		—		6		271
United States government	36		—		1		35
Foreign government	10		—		—		10
Total	10,364		243		79		10,528
At December 31, 2017
Fixed maturity securities:
Corporate	$	5,420	$	246	$	13	$	5,653
States, municipalities and political subdivisions	4,316		155		6		4,465
Commercial mortgage-backed	280		7		1		286
Government-sponsored enterprises	257		1		4		254
United States government	31		—		—		31
Foreign government	10		—		—		10
Subtotal	10,314		409		24		10,699
Equity securities:
Common equities	2,918		3,135		14		6,039
Nonredeemable preferred equities	176		34		—		210
Subtotal	3,094		3,169		14		6,249
Total	$	13,408	$	3,578	$	38	$	16,948

The net unrealized investment gains in our fixed-maturity portfolio at March 31, 2018, are primarily the result of the continued low interest rate environment that increased the fair value of our fixed-maturity portfolio. Our commercial mortgage-backed securities had an average rating of Aa1/AA at March 31, 2018, and December 31, 2017.

At March 31, 2018, JP Morgan Chase & Co. (NYSE:JPM) was our largest single equity holding with a fair value of $248 million, which was 4.2 percent of our publicly traded common equities portfolio and 1.5 percent of the total investment portfolio.

The table below provides fair values and gross unrealized losses by investment category and by the duration of the securities’ continuous unrealized loss positions:



(Dollars in millions)	Less than 12 months				12 months or more				Total
At March 31, 2018	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses
Fixed maturity securities:
Corporate	$	1,002	$	20	$	253	$	15	$	1,255	$	35
States, municipalities and political subdivisions	1,052		21		256		14		1,308		35
Commercial mortgage-backed securities	81		1		35		1		116		2
Government-sponsored enterprises	131		2		123		4		254		6
Foreign government	10		—		—		—		10		—
United States government	24		1		11		—		35		1
Total	$	2,300	$	45	$	678	$	34	$	2,978	$	79
At December 31, 2017
Fixed maturity securities:
Corporate	$	330	$	4	$	252	$	9	$	582	$	13
States, municipalities and political subdivisions	88		1		264		5		352		6
Commercial mortgage-backed	33		—		36		1		69		1
Government-sponsored enterprises	96		1		124		3		220		4
Foreign government	10		—		—		—		10		—
United States government	23		—		6		—		29		—
Subtotal	580		6		682		18		1,262		24
Equity securities:
Common equities	229		14		—		—		229		14
Subtotal	229		14		—		—		229		14
Total	$	809	$	20	$	682	$	18	$	1,491	$	38

Contractual maturity dates for fixed-maturity investments were:



(Dollars in millions)	Amortized cost		Fair value		% of fair value
At March 31, 2018	Amortized cost		Fair value		% of fair value
Maturity dates:
Due in one year or less	$	449	$	457	4.4	%
Due after one year through five years	2,714		2,768		26.3
Due after five years through ten years	3,986		4,046		38.4
Due after ten years	3,215		3,257		30.9
Total	$	10,364	$	10,528	100.0	%

Actual maturities may differ from contractual maturities when there is a right to call or prepay obligations with or without call or prepayment penalties.

The following table provides investment income and investment gains and losses, net:



(Dollars in millions)	Three months ended March 31,
	2018			2017
Investment income:
Interest	$	110		$	111
Dividends	42			39
Other	1			1
Total	153			151
Less investment expenses	3			2
Total	$	150		$	149

Investment gains and losses, net:
Equity securities:
Investment gains and losses on securities sold, net	$	3		$	—
Unrealized gains and losses on securities still held, net	(198		)	—
Gross realized gains	—			153
Gross realized losses	—			(4		)
Subtotal	(195		)	149
Fixed maturities:
Gross realized gains	4			10
Gross realized losses	—			—
Subtotal	4			10

Other	—			1
Total	$	(191	)	$	160

During the three months ended March 31, 2018, there were no fixed-maturity securities other-than-temporarily impaired. During the three months ended March 31, 2017, there were no equity securities and no fixed-maturity securities other-than-temporarily impaired. There were no credit losses on fixed-maturity securities for which a portion of other-than-temporary impairment (OTTI) has been recognized in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017.

At March 31, 2018, 250 fixed-maturity investments with a total unrealized loss of $34 million had been in an unrealized loss position for 12 months or more. Of that total, one fixed-maturity investment had a fair value below 70 percent of amortized cost. At December 31, 2017, 249 fixed-maturity investments with a total unrealized loss of $18 million had been in an unrealized loss position for 12 months or more. Of that total, no fixed-maturity investments had fair values below 70 percent of amortized cost. There were no equity security investments in an unrealized loss position for 12 months or more as of December 31, 2017.