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The amount of adjustment to stockholders' equity associated with an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

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No definition available.

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- Definition

Amount of interest capitalized during the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Allowance for Funds Used during Construction

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

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

-Publisher SEC

-Name Regulation S-X (SX)

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-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

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Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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-Section 45

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

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Basis of Presentation and Summary of Significant Accounting Policies (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Accounting Policies [Line Items]
Current	$ 162		$ 195
Non-current	47		49
Total	209		244
Interest Costs Capitalized	5us-gaap_InterestCostsCapitalized	6us-gaap_InterestCostsCapitalized
Treasury Stock, Shares, Acquired	9.3us-gaap_TreasuryStockSharesAcquired
Treasury Stock, Value, Acquired, Cost Method	202
Treasury Stock Acquired, Average Cost Per Share	$ 21.57
Adjustments Related to Tax Withholding for Share-based Compensation	10
Debt Service
Accounting Policies [Line Items]
Current	12		10
Non-current	24		25
Total	36		35
Rent Reserve
Accounting Policies [Line Items]
Current	2		4
Non-current	0		0
Total	2		4
Construction Major Maintenance
Accounting Policies [Line Items]
Current	60		54
Non-current	17		17
Total	77		71
Security Project Insurance
Accounting Policies [Line Items]
Current	88		127
Non-current	4		5
Total	92		132
Other
Accounting Policies [Line Items]
Current	0		0
Non-current	2		2
Total	$ 2		$ 2
Geothermal Properties, Gross [Member] \| Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	13 years
Geothermal Properties, Gross [Member] \| Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	59 years
Property, Plant and Equipment, Other Types [Member] \| Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Property, Plant and Equipment, Other Types [Member] \| Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	47 years
Building, Machinery and Equipment, Gross [Member] \| Minimum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Building, Machinery and Equipment, Gross [Member] \| Maximum [Member]
Accounting Policies [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	47 years