Investments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Equity in the net earnings of partially owned affiliates	$ 4,467	$ 14,254	$ 32,546	$ 24,836
Centro Energia Ferrara and Centro Energia Teverola [Member]
Equity in the net earnings of partially owned affiliates	0	611	213	3,378
Investment in unconsolidated affiliates	41.65%		41.65%
Waste-to-Energy Project in Italy [Member]
Investment in unconsolidated affiliates	39.00%		39.00%
Wind Farm Project in Italy [Member]
Investment in unconsolidated affiliates	50.00%		50.00%
Refinery / Power Generation Project in Chile [Member]
Investment in unconsolidated affiliates	85.00%		85.00%
Chile [Member]
Equity in the net earnings of partially owned affiliates	2,585	11,195	24,058	14,026
Unconsolidated affiliate insurance recovery assessment receivable, current	66,900		66,900
Debt service letter of credit	10,000		10,000
Guarantee for obligation under Chile based project operation and maintenance agreement	$ 20,000		$ 20,000
Waste-to-energy facility in Camden [Member]
Equity interest in VIE			100.00%

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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

-Publisher FASB

-Name Accounting Standards Codification

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

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-Name Accounting Principles Board Opinion (APB)

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-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 SEC

-Name Regulation S-X (SX)

-Number 210

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

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-Name Accounting Standards Codification

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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+ Details