Basis of Presentation and Accounting Policies Level 4 (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 2,300,000,000	$ 2,200,000,000
Gross Profit Estimates Term for Most Contracts	20 years
Maximum Uncollateralized Threshold for Derivative Counter Party for Single Level Entity	10,000,000
Valuation Allowance, Loss Contingency for Loans, LTV Ratio	90.00%
Participating Dividend to Policyholders	15,000,000	16,000,000	14,000,000
Participating Policies as Percentage of Gross Insurance in Force	1.00%	1.00%	1.00%
Policyholder Dividends, Expense	7,000,000	18,000,000	20,000,000
Depreciation, Depletion and Amortization, Nonproduction	198,000,000	174,000,000	183,000,000
Annuity Obligations	776,000,000	805,000,000
Weighted Average Discount Rate, Percent			4.00%
Allowance for Doubtful Accounts and Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for Doubtful Accounts, Premiums and Other Receivables	131,000,000	125,000,000	117,000,000
Property, Liability and Casualty Insurance Product Line [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage of Net Premium Written Represented by Participating Property and Casualty Insurance Policies	9.00%	10.00%	9.00%
Workers Compensation [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Discounted Deducted From Liabilities	$ 1,000,000,000
Weighted Average Discount Rate, Percent	3.50%	3.50%
Structured Settlements [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Weighted Average Discount Rate, Percent	6.70%
group life term, disability and accident [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Weighted Average Discount Rate, Percent	4.53%	4.71%