Debt (Subsidiary Non-Recourse Debt in Default or Accelerated) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Debt Details [Line Items]
Debt default amount	$ 1,055
Maritza
Debt Details [Line Items]
Net assets	714
Maritza \| Covenant Violation
Debt Details [Line Items]
Debt default amount	850
Kavarna
Debt Details [Line Items]
Net assets	90
Kavarna \| Covenant Violation
Debt Details [Line Items]
Debt default amount	$ 205

The net of assets and liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 225

-Section S99

-Paragraph 3

-Subparagraph (SX 210.6-09.6,7)

-URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606914-122999

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 210

-Section S99

-Paragraph 2

-Subparagraph (SX 210.6-05.4)

-URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e604008-122996

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 05

-Paragraph 4

-Article 6

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Paragraph 19

-Article 6

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant