| **Benefit Plans (Fair Value of Plan Assets Measured on a Recurring Basis) (Details) (USD $)In Millions, unless otherwise specified** | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 |
|--------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|---------------|
| Corporate and other bonds [Member]                                                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | $ 520         | $ 447         |          |
| Corporate and other bonds [Member] | Fair Value, Inputs, Level 1 [Member]                                                            |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Corporate and other bonds [Member] | Fair Value, Inputs, Level 2 [Member]                                                            |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 505           | 436           |          |
| Corporate and other bonds [Member] | Fair Value, Inputs, Level 3 [Member]                                                            |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 15            | 11            | 10            |
| States, municipalities and political subdivisions [Member]                                                                           |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 73            | 91            |          |
| States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 73            | 91            |          |
| States, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 3 [Member]                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Residential mortgage-backed [Member]                                                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 130           | 161           |          |
| Residential mortgage-backed [Member] | Fair Value, Inputs, Level 1 [Member]                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Residential mortgage-backed [Member] | Fair Value, Inputs, Level 2 [Member]                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 130           | 161           |          |
| Residential mortgage-backed [Member] | Fair Value, Inputs, Level 3 [Member]                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Commercial Mortgage Backed Securities [Member]                                                                                       |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 106           | 105           |          |
| Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]                                                |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]                                                |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 106           | 105           |          |
| Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]                                                |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Other asset-backed [Member]                                                                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 12            |          |          |
| Other asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |          |          |
| Other asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 12            |          |          |
| Other asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |          |          |
| Total asset-backed [Member]                                                                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 248           | 266           |          |
| Total asset-backed [Member] | Fair Value, Inputs, Level 1 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Total asset-backed [Member] | Fair Value, Inputs, Level 2 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 248           | 266           |          |
| Total asset-backed [Member] | Fair Value, Inputs, Level 3 [Member]                                                                   |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Fixed Maturities [Member]                                                                                                            |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 841           | 804           |          |
| Fixed Maturities [Member] | Fair Value, Inputs, Level 1 [Member]                                                                     |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Fixed Maturities [Member] | Fair Value, Inputs, Level 2 [Member]                                                                     |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 826           | 793           |          |
| Fixed Maturities [Member] | Fair Value, Inputs, Level 3 [Member]                                                                     |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 15            | 11            | 10            |
| Equity securities [Member]                                                                                                           |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 605           | 493           |          |
| Equity securities [Member] | Fair Value, Inputs, Level 1 [Member]                                                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 480           | 386           |          |
| Equity securities [Member] | Fair Value, Inputs, Level 2 [Member]                                                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 117           | 102           |          |
| Equity securities [Member] | Fair Value, Inputs, Level 3 [Member]                                                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 8             | 5             | 5             |
| Derivative Financial Instruments, Assets [Member]                                                                                    |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 2             | 1             |          |
| Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member]                                             |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 2             | 1             |          |
| Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]                                             |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]                                             |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Short-term Investments [Member]                                                                                                      |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 94            | 119           |          |
| Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]                                                               |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 45            | 37            |          |
| Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]                                                               |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 49            | 82            |          |
| Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member]                                                               |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Hedge Funds [Member]                                                                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 969           | 896           |          |
| Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member]                                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]                                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 647           | 537           |          |
| Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]                                                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 322           | 359           | 330           |
| Private Equity Funds [Member]                                                                                                        |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 114           | 62            |          |
| Private Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member]                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Private Equity Funds [Member] | Fair Value, Inputs, Level 2 [Member]                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Private Equity Funds [Member] | Fair Value, Inputs, Level 3 [Member]                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 114           | 62            | 65            |
| Total limited partnerships [Member]                                                                                                  |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 1,083         | 958           |          |
| Total limited partnerships [Member] | Fair Value, Inputs, Level 1 [Member]                                                           |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Total limited partnerships [Member] | Fair Value, Inputs, Level 2 [Member]                                                           |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 647           | 537           |          |
| Total limited partnerships [Member] | Fair Value, Inputs, Level 3 [Member]                                                           |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 436           | 421           | 395           |
| Other Assets [Member]                                                                                                                |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 31            | 40            |          |
| Other Assets [Member] | Fair Value, Inputs, Level 1 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Other Assets [Member] | Fair Value, Inputs, Level 2 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 31            | 40            |          |
| Other Assets [Member] | Fair Value, Inputs, Level 3 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     |     |          |
| Investment Contracts with Insurance Company [Member]                                                                                 |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |          | 10            |          |
| Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 1 [Member]                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |          |     |          |
| Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 2 [Member]                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |          |     |          |
| Investment Contracts with Insurance Company [Member] | Fair Value, Inputs, Level 3 [Member]                                          |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            |     | 10            | 10            |
| Total assets [Member]                                                                                                                |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 2,656         | 2,425         |          |
| Total assets [Member] | Fair Value, Inputs, Level 1 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 527           | 424           |          |
| Total assets [Member] | Fair Value, Inputs, Level 2 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | 1,670         | 1,554         |          |
| Total assets [Member] | Fair Value, Inputs, Level 3 [Member]                                                                         |          |          |          |
| **Defined benefit plan disclosure [Line items]**                                                                                     |          |          |          |
| Fair value of plan assets                                                                                                            | $ 459         | $ 447         | $ 420         |

| X                                                                                                                                                                         |
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| - Details**Name:**us-gaap_DefinedBenefitPlanDisclosureLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930
+ Details**Name:**us-gaap_DefinedBenefitPlanFairValueOfPlanAssets**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |