|
Debt (Letter of Credit) (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2015
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Dec. 31, 2014
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|---|---|---|---|---|---|---|
| Line of Credit Facility [Line Items] | ||||||
| Letters of Credit Outstanding, Amount | $ 623 | $ 644 | ||||
| Corporate Revolving Facility [Member] | ||||||
| Line of Credit Facility [Line Items] | ||||||
| Letters of Credit Outstanding, Amount | 202 | [1] | 223 | [1] | ||
| CDH [Member] | ||||||
| Line of Credit Facility [Line Items] | ||||||
| Letters of Credit Outstanding, Amount | 235 | 214 | ||||
| Various Project Financing Facilities [Member] | ||||||
| Line of Credit Facility [Line Items] | ||||||
| Letters of Credit Outstanding, Amount | $ 186 | $ 207 | ||||
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