Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Value Hierarchy for Assets Measured at Fair Value on a Recurring Basis

The following tables illustrate the fair value hierarchy for those assets measured at fair value on a recurring basis at March 31, 2018, and December 31, 2017. We do not have any liabilities carried at fair value. There were no transfers between Level 1 and Level 2.

(Dollars in millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At March 31, 2018
Fixed maturities, available for sale:
Corporate	$	—	$	5,571	$	1	$	5,572
States, municipalities and political subdivisions	—		4,350		4		4,354
Commercial mortgage-backed	—		286		—		286
Government-sponsored enterprises	—		271		—		271
United States government	35		—		—		35
Foreign government	—		10		—		10
Subtotal	35		10,488		5		10,528
Common equities	5,893		—		—		5,893
Nonredeemable preferred equities	—		193		—		193
Separate accounts taxable fixed maturities	—		793		—		793
Top Hat savings plan mutual funds and common equity (included in Other assets)	34		—		—		34
Total	$	5,962	$	11,474	$	5	$	17,441
At December 31, 2017
Fixed maturities, available for sale:
Corporate	$	—	$	5,652	$	1	$	5,653
States, municipalities and political subdivisions	—		4,460		5		4,465
Commercial mortgage-backed	—		286		—		286
Government-sponsored enterprises	—		254		—		254
United States government	31		—		—		31
Foreign government	—		10		—		10
Subtotal	31		10,662		6		10,699
Common equities, available for sale	6,039		—		—		6,039
Nonredeemable preferred equities, available for sale	—		210		—		210
Separate accounts taxable fixed maturities	—		795		—		795
Top Hat savings plan mutual funds and common   equity (included in Other assets)	31		—		—		31
Total	$	6,101	$	11,667	$	6	$	17,774

Asset Fair Value Measurements Using Significant Unobservable Inputs (Level 3)

The following table provides the change in Level 3 assets for the three months ended March 31:

(Dollars in millions)	Asset fair value measurements using significant unobservable inputs
		Corporate fixed maturities			States, municipalities and political subdivisions fixed maturities			Total
Beginning balance, January 1, 2018		$	1		$	5		$	6
Total gains or losses (realized/unrealized):
Included in net income (loss)		—			—			—
Included in other comprehensive income (loss)		—			(1		)	(1		)
Purchases		—			—			—
Sales		—			—			—
Transfers into Level 3		—			—			—
Transfers out of Level 3		—			—			—
Ending balance, March 31, 2018		$	1		$	4		$	5
Beginning balance, January 1, 2017		$	78		$	—		$	78
Total gains or losses (realized/unrealized):
Included in net income		—			—			—
Included in other comprehensive income		—			—			—
Purchases		—			—			—
Sales		—			—			—
Transfers into Level 3		—			—			—
Transfers out of Level 3		(77		)	—			(77		)
Ending balance, March 31, 2017		$	1		$	—		$	1

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

This table summarizes the book value and principal amounts of our long-term debt:

(Dollars in millions)				Book value				Principal amount
Interest rate		Year of  issue		March 31,		December 31,		March 31,		December 31,
				2018		2017		2018		2017
6.900	%	1998	Senior debentures, due 2028	$	26	$	26	$	28	$	28
6.920	%	2005	Senior debentures, due 2028	391		391		391		391
6.125	%	2004	Senior notes, due 2034	370		370		374		374
			Total	$	787	$	787	$	793	$	793

Fair Value of Life Policy Loans

The following table shows the fair value of our life policy loans included in other invested assets:

(Dollars in millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At March 31, 2018
Life policy loans	$	—	$	—	$	40	$	40
At December 31, 2017
Life policy loans	$	—	$	—	$	41	$	41

Debt

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Values of Deferred Annuities, Structured Settlements and Other Items

The following table shows fair values of our note payable and long-term debt:

(Dollars in millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At March 31, 2018
Note payable	$	—	$	24	$	—	$	24
6.900% senior debentures, due 2028	—		33		—		33
6.920% senior debentures, due 2028	—		490		—		490
6.125% senior notes, due 2034	—		464		—		464
Total	$	—	$	1,011	$	—	$	1,011
At December 31, 2017
Note payable	$	—	$	24	$	—	$	24
6.900% senior debentures, due 2028	—		34		—		34
6.920% senior debentures, due 2028	—		505		—		505
6.125% senior notes, due 2034	—		477		—		477
Total	$	—	$	1,040	$	—	$	1,040

Deferred Annuities, Structured Settlements, And Other

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair Values of Deferred Annuities, Structured Settlements and Other Items

The following table shows fair values of our deferred annuities and structured settlements included in life policy and investment contract reserves:

(Dollars in millions)	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
At March 31, 2018
Deferred annuities	$	—	$	—	$	788	$	788
Structured settlements	—		200		—		200
Total	$	—	$	200	$	788	$	988
At December 31, 2017
Deferred annuities	$	—	$	—	$	834	$	834
Structured settlements	—		210		—		210
Total	$	—	$	210	$	834	$	1,044