Investments (Tables)

12 Months Ended

Dec. 31, 2015

Investments [Abstract]

Net investment income

The significant components of Net investment income are presented in the following table.

Years ended December 31
(In millions)	2015			2014			2013
Fixed maturity securities	$	1,751		$	1,803		$	1,827
Equity securities	12			12			12
Limited partnership investments	92			263			451
Mortgage loans	33			31			23
Short term investments	6			3			3
Trading portfolio	8			10			17
Other	1			3			2
Gross investment income	1,903			2,125			2,335
Investment expense	(63		)	(58		)	(53		)
Net investment income	$	1,840		$	2,067		$	2,282

Net realized investment gains (losses)

Net realized investment gains (losses) are presented in the following table.

Years ended December 31
(In millions)	2015			2014			2013
Net realized investment gains (losses):
Fixed maturity securities:
Gross realized gains	$	131		$	170		$	185
Gross realized losses	(197		)	(129		)	(144		)
Net realized investment gains (losses) on fixed maturity securities	(66		)	41			41
Equity securities:
Gross realized gains	2			8			13
Gross realized losses	(25		)	(7		)	(35		)
Net realized investment gains (losses) on equity securities	(23		)	1			(22		)
Derivatives	10			(1		)	(9		)
Short term investments and other	12			16			10
Net realized investment gains (losses)	$	(67	)	$	57		$	20

Net change in unrealized gains (losses) on investments

Net change in unrealized gains on investments is presented in the following table.

Years ended December 31
(In millions)	2015			2014		2013
Net change in unrealized gains on investments:
Fixed maturity securities	$	(1,114	)	$	1,511	$	(2,541	)
Equity securities	(6		)	6		(15		)
Other	1			—		—
Total net change in unrealized gains on investments	$	(1,119	)	$	1,517	$	(2,556	)

Components of net other than temporary impairment losses recognized in earnings by asset type

The components of OTTI losses recognized in earnings by asset type are presented in the following table.

Years ended December 31
(In millions)	2015		2014		2013
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	104	$	18	$	20
States, municipalities and political subdivisions	18		46		—
Asset-backed:
Residential mortgage-backed	8		5		19
Other asset-backed	1		1		2
Total asset-backed	9		6		21
Total fixed maturity securities available-for-sale	131		70		41
Equity securities available-for-sale:
Common stock	25		7		8
Preferred stock	—		—		26
Total equity securities available-for-sale	25		7		34
Short term investments	—		—		1
OTTI losses recognized in earnings	$	156	$	77	$	76

Summary of fixed maturity and equity securities

The following tables present a summary of fixed maturity and equity securities.

December 31, 2015	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Unrealized OTTI Losses (Gains)
(In millions)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	17,080	$	1,019	$	342	$	17,757	$	—
States, municipalities and political subdivisions	11,729		1,453		8		13,174		(4		)
Asset-backed:
Residential mortgage-backed	4,935		154		17		5,072		(37		)
Commercial mortgage-backed	2,154		55		12		2,197		—
Other asset-backed	923		6		8		921		—
Total asset-backed	8,012		215		37		8,190		(37		)
U.S. Treasury and obligations of government-sponsored enterprises	62		5		—		67		—
Foreign government	334		13		1		346		—
Redeemable preferred stock	33		2		—		35		—
Total fixed maturity securities available-for-sale	37,250		2,707		388		39,569		$	(41	)
Total fixed maturity securities trading	3						3
Equity securities available-for-sale:
Common stock	46		3		1		48
Preferred stock	145		7		3		149
Total equity securities available-for-sale	191		10		4		197
Total	$	37,444	$	2,717	$	392	$	39,769

December 31, 2014	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Unrealized OTTI Losses (Gains)
(In millions)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	17,210	$	1,721	$	61	$	18,870	$	—
States, municipalities and political subdivisions	11,285		1,463		8		12,740		—
Asset-backed:
Residential mortgage-backed	5,028		218		13		5,233		(53		)
Commercial mortgage-backed	2,056		93		5		2,144		(2		)
Other asset-backed	1,234		11		10		1,235		—
Total asset-backed	8,318		322		28		8,612		(55		)
U.S. Treasury and obligations of government-sponsored enterprises	26		5		—		31		—
Foreign government	438		16		—		454		—
Redeemable preferred stock	39		3		—		42		—
Total fixed maturity securities available-for-sale	37,316		3,530		97		40,749		$	(55	)
Total fixed maturity securities trading	19						19
Equity securities available-for-sale:
Common stock	38		9		—		47
Preferred stock	172		5		2		175
Total equity securities available-for-sale	210		14		2		222
Total	$	37,545	$	3,544	$	99	$	40,990

Securities in a gross unrealized loss position

The following tables present the estimated fair value and gross unrealized losses of fixed maturity and equity securities in a gross unrealized loss position by the length of time in which the securities have continuously been in that position.

	Less than 12 Months				12 Months or Longer				Total
December 31, 2015	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
(In millions)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	4,882	$	302	$	162	$	40	$	5,044	$	342
States, municipalities and political subdivisions	338		8		75		—		413		8
Asset-backed:
Residential mortgage-backed	963		9		164		8		1,127		17
Commercial mortgage-backed	652		10		96		2		748		12
Other asset-backed	552		8		5		—		557		8
Total asset-backed	2,167		27		265		10		2,432		37
U.S. Treasury and obligations of government-sponsored enterprises	4		—		—		—		4		—
Foreign government	54		1		—		—		54		1
Redeemable preferred stock	3		—		—		—		3		—
Total fixed maturity securities available-for-sale	7,448		338		502		50		7,950		388
Equity securities available-for-sale:
Common Stock	3		1		—		—		3		1
Preferred stock	13		3		—		—		13		3
Total equity securities available-for-sale	16		4		—		—		16		4
Total	$	7,464	$	342	$	502	$	50	$	7,966	$	392

	Less than 12 Months				12 Months or Longer				Total
December 31, 2014	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
(In millions)
Fixed maturity securities available-for-sale:
Corporate and other bonds	$	1,330	$	46	$	277	$	15	$	1,607	$	61
States, municipalities and political subdivisions	335		5		127		3		462		8
Asset-backed:
Residential mortgage-backed	293		5		189		8		482		13
Commercial mortgage-backed	264		2		99		3		363		5
Other asset-backed	607		10		7		—		614		10
Total asset-backed	1,164		17		295		11		1,459		28
U.S. Treasury and obligations of government-sponsored enterprises	3		—		4		—		7		—
Foreign government	3		—		3		—		6		—
Redeemable preferred stock	3		—		—		—		3		—
Total fixed maturity securities available-for-sale	2,838		68		706		29		3,544		97
Equity securities available-for-sale:
Preferred stock	17		2		1		—		18		2
Total	$	2,855	$	70	$	707	$	29	$	3,562	$	99

Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI

The following table presents the activity related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held as of December 31, 2015, 2014 and 2013 for which a portion of an OTTI loss was recognized in Other comprehensive income.

Years ended December 31
(In millions)	2015			2014			2013
Beginning balance of credit losses on fixed maturity securities	$	62		$	74		$	95
Additional credit losses for securities for which an OTTI loss was previously recognized	—			—			2
Reductions for securities sold during the period	(9		)	(9		)	(23		)
Reductions for securities the Company intends to sell or more likely than not will be required to sell	—			(3		)	—
Ending balance of credit losses on fixed maturity securities	$	53		$	62		$	74

Contractual maturity

The following table presents available-for-sale fixed maturity securities by contractual maturity.

December 31	2015				2014
(In millions)	Cost or Amortized Cost		Estimated Fair Value		Cost or Amortized Cost		Estimated Fair Value
Due in one year or less	$	1,574	$	1,595	$	2,479	$	2,511
Due after one year through five years	7,721		8,070		9,054		9,605
Due after five years through ten years	14,652		14,915		12,055		12,584
Due after ten years	13,303		14,989		13,728		16,049
Total	$	37,250	$	39,569	$	37,316	$	40,749

Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments

The following tables present the aggregate contractual or notional amount and estimated fair value related to derivative financial instruments.

December 31, 2015	Contractual/ Notional Amount		Estimated Fair Value
(In millions)			Asset		Liability
Without hedge designation
Equity warrants	$	5	$	—	$	—
Embedded derivative on funds withheld liability	179		—		(5		)
Total			$	—	$	(5	)

December 31, 2014	Contractual/ Notional Amount		Estimated Fair Value
(In millions)			Asset		Liability
Without hedge designation
Currency forwards	$	9	$	—	$	—
Equity warrants	5		—		—
Embedded derivative on funds withheld liability	184		—		3
Total			$	—	$	3