|
Risk Management Activities and Fair Value Measurements - Derivative Notional Amounts and Fair Value (Details) (USD $)
In Millions, unless otherwise specified |
Sep. 30, 2013
|
Jun. 30, 2013
|
|---|---|---|
|
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member]
|
||
| Derivative [Line Items] | ||
| Notional amount | $ 951 | $ 951 |
| Fair Value Asset (Liability) | 164 | 168 |
|
Fair Value Hedging [Member] | Interest Rate Contract [Member]
|
||
| Derivative [Line Items] | ||
| Notional amount | 10,226 | 9,117 |
| Fair Value Asset (Liability) | 103 | 132 |
|
Net Investment Hedging [Member]
|
||
| Derivative [Line Items] | ||
| Notional amount | 1,303 | 1,303 |
| Fair Value Asset (Liability) | 223 | 233 |
|
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
|
||
| Derivative [Line Items] | ||
| Notional amount | 6,496 | 7,080 |
| Fair Value Asset (Liability) | $ (2) | $ (71) |