| **Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule of Long Term Debt of Registrant) (Details) (USD $)In Millions, unless otherwise specified** | Dec. 31, 2011 | Dec. 31, 2010 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Short term debt:**                                                                                                                                                                |          |          |
| Other debt                                                                                                                                                                          | $ 13          | $ 1           |
| Total short term debt                                                                                                                                                               | 83            | 400           |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Debenture, 7.250%, face amount $243, due November 15, 2023                                                                                                                          | 241           | 241           |
| Other long-term debt                                                                                                                                                                |     | 23            |
| Total long term debt                                                                                                                                                                | 2,525         | 2,251         |
| Total                                                                                                                                                                               | 2,608         | 2,651         |
| Parent Company [Member]                                                                                                                                                             |          |          |
| **Short term debt:**                                                                                                                                                                |          |          |
| Other debt                                                                                                                                                                          | 3             |     |
| Total short term debt                                                                                                                                                               | 3             | 399           |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Debenture, 7.250%, face amount $243, due November 15, 2023                                                                                                                          | 241           | 241           |
| Other long-term debt                                                                                                                                                                |     | 3             |
| Total long term debt                                                                                                                                                                | 2,525         | 2,131         |
| Total                                                                                                                                                                               | 2,528         | 2,530         |
| Senior notes 6.000%, face amount of $400, due August 15, 2011 [Member]                                                                                                              |          |          |
| **Short term debt:**                                                                                                                                                                |          |          |
| Senior notes, current                                                                                                                                                               |     | 399           |
| Senior notes 6.000%, face amount of $400, due August 15, 2011 [Member] | Parent Company [Member]                                                                                    |          |          |
| **Short term debt:**                                                                                                                                                                |          |          |
| Senior notes, current                                                                                                                                                               |     | 399           |
| Senior notes 5.850%, face amount $549, due December 15, 2014 [Member]                                                                                                               |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 548           | 548           |
| Senior notes 5.850%, face amount $549, due December 15, 2014 [Member] | Parent Company [Member]                                                                                     |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 548           | 548           |
| Senior notes 6.500%, face amount of $350, due August 15, 2016 [Member]                                                                                                              |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 348           | 347           |
| Senior notes 6.500%, face amount of $350, due August 15, 2016 [Member] | Parent Company [Member]                                                                                    |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 348           | 347           |
| Senior notes 6.950%, face amount $150, due January 15, 2018 [Member]                                                                                                                |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 149           | 149           |
| Senior notes 6.950%, face amount $150, due January 15, 2018 [Member] | Parent Company [Member]                                                                                      |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 149           | 149           |
| Senior notes 7.350%, face amount $350, due November 15, 2019 [Member]                                                                                                               |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 348           | 348           |
| Senior notes 7.350%, face amount $350, due November 15, 2019 [Member] | Parent Company [Member]                                                                                     |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 348           | 348           |
| Senior notes 5.875%, face amount $500, due August 15, 2020 [Member]                                                                                                                 |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 495           | 495           |
| Senior notes 5.875%, face amount $500, due August 15, 2020 [Member] | Parent Company [Member]                                                                                       |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 495           | 495           |
| Senior notes 5.750%, face amount $400, due August 15, 2021 [Member]                                                                                                                 |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | 396           |     |
| Senior notes 5.750%, face amount $400, due August 15, 2021 [Member] | Parent Company [Member]                                                                                       |          |          |
| **Long term debt:**                                                                                                                                                                 |          |          |
| Senior notes, noncurrent                                                                                                                                                            | $ 396         |     |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments, excluding current portion.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total of the portions of the carrying amounts as of the balance sheet date of long-term debt, which may include notes payable, bonds payable, debentures, mortgage loans, and commercial paper, which are scheduled to be repaid within one year or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of the portion of long-term debt not otherwise specified in the taxonomy that is scheduled to be repaid within one year or the normal operating cycle, if longer.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of debt not otherwise defined (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying value as of the balance sheet date of the portion of long-term notes having the highest claim on the assets of the issuer in case of bankruptcy or liquidation, due within one year or the normal operating cycle, if longer. Senior note holders are paid off in full before any payments are made to debt holders having a lesser priority of repayment.
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