This item represents the aggregate carrying amount of all cost-method investments as reported on or included in the balance sheet. The original cost of the investments may differ from the aggregate carrying amount disclosed due to various adjustments such as: (i) dividends received in excess of earnings after the date of investment that are considered a return of investment and therefore recorded as reductions to cost of the investment, or (ii) a series of operating losses of an investee or other factors which may indicate that a decrease in value of the investment has occurred which is other than temporary and accordingly such decrease in value has been recognized.

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 6

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.12)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 18

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6383889&loc=d3e40346-111594

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 03-1

-Paragraph 22

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References+ Details

Variable Interest Entities (Unconsolidated) (Details) (USD $) In Millions, unless otherwise specified														1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Variable Interest Entity, Deconsolidated	Dec. 31, 2011 Variable Interest Entity, Deconsolidated	Dec. 31, 2012 San Juan Mesa Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Elkhorn Ridge Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Sunrise Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Sycamore Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Watson Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Covanta Huntington L.P. Variable Interest Entity, Deconsolidated	Dec. 31, 2011 Covanta Huntington L.P. Variable Interest Entity, Deconsolidated	Dec. 31, 2012 Doga Enerji	Dec. 31, 2011 Doga Enerji	Jan. 31, 2013 Subsequent Event Covanta Huntington L.P. Variable Interest Entity, Deconsolidated
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
Minimum percentage of loss before income tax required in order for the investment to be disclosed individually (as a percent)			5.00%
Minimum equity investment balance required in order for the investment to be disclosed individually.			$ 40
Equity investment			527	515	80	81	181	40	40
Ownership interest in unconsolidated affiliate (as a percent)					75.00%	67.00%	50.00%	50.00%	49.00%
Cost investment			7	8
Total	534	523	534	523
Cost method investment, ownership percentage (as a percent)										38.00%	38.00%	80.00%	80.00%
Cash received from sale of ownership in project														$ 7.5