Investments (Tables)

6 Months Ended

Jun. 30, 2017

Investment [Line Items]

Impaired commercial mortgage loans and related valuation reserves

		June 30, 2017					December 31, 2016
(In millions)		Gross		Reserves		Net		Gross		Reserves		Net
Impaired commercial mortgage loans with valuation reserves	$	6	$	(1)	$	5	$	26	$	(5)	$	21
Impaired commercial mortgage loans without valuation reserves		-		-		-		-		-		-
Total impaired commercial mortgage loans	$	6	$	(1)	$	5	$	26	$	(5)	$	21

Schedule of short-term investments and cash equivalents

		June 30,		December 31,
(In millions)		2017		2016
Corporate securities	$	1,700	$	2,234
Federal government securities	$	673	$	378
Foreign government securities	$	109	$	94
Money market funds	$	20	$	11

Realized gains and losses on investments

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In millions)	2017		2016		2017		2016
Fixed maturities	$	14	$	6	$	16	$	(12)
Equity securities		1		11		34		1
Commercial mortgage loans		(1)		4		(1)		4
Other investments, including derivatives		37		46		48		42
Realized investment gains before income taxes		51		67		97		35
Less income taxes		17		23		32		12
Net realized investment gains	$	34	$	44	$	65	$	23

Sales information for available-for-sale fixed maturities and equity securities

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In millions)	2017		2016		2017		2016
Proceeds from sales	$	516	$	351	$	930	$	712
Gross gains on sales	$	12	$	22	$	59	$	34
Gross losses on sales	$	2	$	1	$	4	$	6

Fixed Maturities [Member]

Investment [Line Items]

Investment maturities

		Amortized		Fair
(In millions)		Cost		Value
Due in one year or less	$	1,393	$	1,407
Due after one year through five years		6,822		7,079
Due after five years through ten years		8,905		9,176
Due after ten years		3,649		4,368
Mortgage and other asset-backed securities		453		483
Total fixed maturities	$	21,222	$	22,513

Gross unrealized appreciation (depreciation) on fixed maturities

				Gross		Gross
				Unrealized		Unrealized
		Amortized		Appre-		Depre-		Fair
		Cost		ciation		ciation		Value
(In millions)	June 30, 2017
Federal government and agency	$	663	$	240	$	(3)	$	900
State and local government		1,277		106		(2)		1,381
Foreign government		2,202		125		(14)		2,313
Corporate		16,627		877		(68)		17,436
Mortgage and other asset-backed		453		32		(2)		483
Total fixed maturities	$	21,222	$	1,380	$	(89)	$	22,513
(In millions)	December 31, 2016
Federal government and agency	$	658	$	223	$	(4)	$	877
State and local government		1,342		99		(6)		1,435
Foreign government		1,998		129		(14)		2,113
Corporate		15,483		716		(149)		16,050
Mortgage and other asset-backed		461		29		(4)		486
Total fixed maturities	$	19,942	$	1,196	$	(177)	$	20,961

Fixed maturities with a decline in fair value from amortized cost

	June 30, 2017
	Fair		Amortized		Unrealized		Number
(Dollars in millions)	Value		Cost		Depreciation		of Issues
One year or less:
Investment grade	$	3,449	$	3,515	$	(66)	791
Below investment grade	$	399	$	408	$	(9)	401
More than one year:
Investment grade	$	220	$	229	$	(9)	40
Below investment grade	$	71	$	76	$	(5)	14

Commercial Mortgage Loans [Member]

Investment [Line Items]

Credit risk profile of commercial mortgage loan portfolio

(In millions)
		Debt Service Coverage Ratio
		1.30x or		1.20x to		1.10x to		1.00x to		Less than
Loan-to-Value Ratios		Greater		1.29x		1.19x		1.09x		1.00x		Total
As of June 30, 2017
Below 50%	$	354	$	15	$	-	$	-	$	30	$	399
50% to 59%		635		27		-		-		15		677
60% to 69%		541		-		-		-		-		541
70% to 79%		84		-		-		-		35		119
80% to 89%		-		-		-		-		-		-
90% to 100%		-		-		-		-		5		5
Total	$	1,614	$	42	$	-	$	-	$	85	$	1,741
As of December 31, 2016
Below 50%	$	335	$	15	$	-	$	-	$	-	$	350
50% to 59%		517		46		-		30		-		593
60% to 69%		624		14		-		-		-		638
70% to 79%		-		-		29		-		35		64
80% to 89%		-		-		-		-		-		-
90% to 100%		-		-		-		-		21		21
Total	$	1,476	$	75	$	29	$	30	$	56	$	1,666