| **Schedule II. Condensed Financial Information of Registrant (Parent Company) (Schedule II. Condensed Financial Information of Registrant (Narrative)) (Details) (USD $)In Millions, unless otherwise specified** | Dec. 31, 2014                                                                                                                                                             | Dec. 31, 2013                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------|
| Guarantor Obligations, Maximum Exposure, Undiscounted                                                                                                                                                             | $ 1,900us-gaap_GuaranteeObligationsMaximumExposure                                                                                                                        |                                                                                                |
| Guarantor Obligations, Current Carrying Value                                                                                                                                                                     | 5us-gaap_GuaranteeObligationsCurrentCarryingValue                                                                                                                         | 7us-gaap_GuaranteeObligationsCurrentCarryingValue                                                   |
| Parent Company [Member]                                                                                                                                                                                           |                                                                                                                                                                      |                                                                                                |
| Guarantor Obligations, Maximum Exposure, Undiscounted                                                                                                                                                             | 1,900us-gaap_GuaranteeObligationsMaximumExposure/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                                                                        |                                                                                                |
| Guarantor Obligations, Current Carrying Value                                                                                                                                                                     | 5us-gaap_GuaranteeObligationsCurrentCarryingValue/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember                                                                       | 0us-gaap_GuaranteeObligationsCurrentCarryingValue/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember |
| Indemnification Agreement [Member] | Parent Company [Member]                                                                                                                                                      |                                                                                                                                                                      |                                                                                                |
| Guarantor Obligations, Maximum Exposure, Undiscounted                                                                                                                                                             | $ 625us-gaap_GuaranteeObligationsMaximumExposure/ dei_LegalEntityAxis= us-gaap_ParentCompanyMember/ us-gaap_StatementScenarioAxis= us-gaap_IndemnificationGuaranteeMember |                                                                                                |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248
+ Details**Name:**us-gaap_GuaranteeObligationsCurrentCarryingValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248
+ Details**Name:**us-gaap_GuaranteeObligationsMaximumExposure**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**dei_LegalEntityAxis=us-gaap_ParentCompanyMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementScenarioAxis=us-gaap_IndemnificationGuaranteeMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |