| **Fair Value Fair Value (Narrative) (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 9 Months Ended |
|------------------------------------------------------------------------------------------------|----------------|----------------|
||
| Fair Value, Level 2 to level 1 Transfers, Amount                                               | $ 106          |           | $ 106 |   |
| Fair Value, Level 1 to level 2 Transfers, Amount                                               |      |      |    |    |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the transfers of assets or liabilities measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258
+ Details**Name:**us-gaap_FairValueLevel1ToLevel2TransfersAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the transfers of assets or liabilities measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258
+ Details**Name:**us-gaap_FairValueLevel2ToLevel1TransfersAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |