| **Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)In Millions, unless otherwise specified**            | 12 Months Ended          |
|--------------------------------------------------------------------------------------------------------------------------------|--------------------------|
||
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Number of operating subsidaries                                                                                                | 2                        |   |   |   |
| Number of independent insurance agencies                                                                                       | 1,450                    |   |   |   |
| Number of reporting locations                                                                                                  | 1,823                    |   |   |   |
| Number of states in which entity operates                                                                                      | 39                       |   |   |   |
| Defined Benefit Plan Qualifying Age                                                                                            |                     |   |   | 40 years |
| Depreciation expense                                                                                                           | $ 37                     | $ 37 | $ 46 |   |
| Land, building and equipment impairments                                                                                       | 0                        | 0 | 0 |   |
| Weighted-average remaining contractual life for exercisable awards                                                             | 3 years 2 months 12 days |   |   |   |
| Current fair value of the BOLI invested assets and cash exceeded the current fair value of the contract holders' account value | 8                        |   |   |   |
| Other invested assets                                                                                                          | 68                       | 68 |   |   |
| Minimum [Member]                                                                                                               |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Estimated useful lives                                                                                                         | 3 years                  |   |   |   |
| Maximum [Member]                                                                                                               |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Estimated useful lives                                                                                                         | 39 years 6 months        |   |   |   |
| Life Policy Loans [Member]                                                                                                     |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Other invested assets                                                                                                          | 36                       |   |   |   |
| Venture Capital Funds [Member]                                                                                                 |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Other invested assets                                                                                                          | $ 32                     |   |   |   |
| 10 Largest States [Member]                                                                                                     |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 63.80%                   | 65.40% |   |   |
| Ohio, Largest State [Member]                                                                                                   |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 18.50%                   | 19.10% |   |   |
| Illinois, Indiana, Pennsylvania, Georgia, North Carolina, and Michigan [Member] | Minimum [Member]                             |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 4.00%                    |   |   |   |
| Illinois, Indiana, Pennsylvania, Georgia, North Carolina, and Michigan [Member] | Maximum [Member]                             |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 8.00%                    |   |   |   |
| Largest Single Agency Relationship [Member]                                                                                    |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 0.80%                    |   |   |   |
| All Other [Member] | Maximum [Member]                                                                                          |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Generated percentage of total earned premiums                                                                                  | 2.10%                    |   |   |   |
| Restricted Stock Units [Member]                                                                                                |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Awards vesting period                                                                                                          | 3 years                  |   |   |   |
| Stock Options [Member]                                                                                                         |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Awards vesting period                                                                                                          | 3 years                  |   |   |   |
| Weighted-average remaining contractual life for exercisable awards                                                             | 10 years                 |   |   |   |
| Property Casualty Insurance Segment [Member]                                                                                   |                     |   |   |   |
| **Significant Accounting Policies [Line Items]**                                                                               |                     |   |   |   |
| Number of operating subsidaries                                                                                                | 2                        |   |   |   |

| X                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Age at which participants could elect to remain in the defined benefit plan as of August 31, 2008.
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| X                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Independent Insurance Agencies and Brokerages
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| X                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of Locations
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| X                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of Subsidiaries
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| X                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of earned premiums.
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| X                                                                                                                                                                    |
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.
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| X                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of states the entity operates in as of the balance sheet date.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other investments not otherwise specified in the taxonomy.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.
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| - Definition
Fair value amount of the specified investment category of assets maintained in separate accounts as of the balance sheet date.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
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| - Definition
Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
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