Fair Value (Quantitative Information About Significant Unobservable Inputs Utilized By Company Fair Value Measurements Of Level 3 Assets) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Fixed Maturity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected maturity date in years	2.2
Private offering price per unit	$ 26.5
Fixed Maturity Securities [Member] | Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected maturity date in years	5.5
Fixed Maturity Securities [Member] | Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected maturity date in years	0.5
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Private offering price per share	$ 211.01
Equity Securities [Member] | Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Private offering price per share	$ 4,023.00
Equity Securities [Member] | Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Private offering price per share	$ 0.10
Life Settlement Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rate risk premium	9.00%
Mortality assumption	181.00%
Life Settlement Contracts [Member] | Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortality assumption	928.00%
Life Settlement Contracts [Member] | Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortality assumption	65.00%
Discounted Cash Flow [Member] | Fixed Maturity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assets	204
Valuation Technique(s)	Discounted cash flow
Discounted Cash Flow [Member] | Life Settlement Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assets	115
Valuation Technique(s)	Discounted cash flow
Market Approach [Member] | Fixed Maturity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assets	53
Valuation Technique(s)	Market approach
Market Approach [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value Assets	$ 69
Valuation Technique(s)	Market approach