Policyholder Account Balances, Future Policy Benefits and Claims and Separate Account Liabilities (Text) (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Fixed annuities liabilities average interest rate	4.09%
Policy claims and other policyholders' funds	$ 903	$ 884
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses	$ 41	24	$ 2
Minimum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Fixed annuities liabilities interest rates	2.71%
Maximum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Fixed annuities liabilities interest rates	9.38%
EIA host values [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Equity Indexed Annuity Contract Initial Term	7 years
Minimum interest rate guarantee	3.00%
Percentage of initial premium receiving interest guarantee	90.00%
LTC insurance [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Unpaid reported claims interest rate	6.25%
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses	$ 50
LTC insurance [Member] | Minimum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	6.00%
LTC insurance [Member] | Maximum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	6.40%
Life, DI and LTC insurance [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Policy claims and other policyholders' funds	$ 1,300	1,200
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses		6	60
Property and Casualty [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Policy claims and other policyholders' funds	722	683
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses		18	$ (58)
Auto and Home [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses		20
Catastrophe Insurance [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Change in liability for prior year incurred unpaid reported claims and claim adjustment expenses	$ (9)	$ (2)
DI [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Unpaid reported claims interest rate	4.50%
DI [Member] | Minimum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	3.75%
DI [Member] | Maximum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	7.50%
Term and whole life insurance [Member] | Minimum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	3.00%
Term and whole life insurance [Member] | Maximum [Member]
Liability for Policyholder Account Balances and Future Policy Benefits and Policy Claims and Other Policyholders Funds [Line Items]
Anticipated interest rate for future claims	10.00%