CHANGES IN CAPITALIZATION - Additional Information (Detail) (USD $)	3 Months Ended										3 Months Ended																3 Months Ended				3 Months Ended		3 Months Ended			1 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Employee Restricted Equity Awards	Mar. 31, 2012 Restricted stock units	Mar. 31, 2012 Foreign Subsidiaries	Mar. 31, 2012 Minimum	Mar. 31, 2012 Federal funds rate	Mar. 31, 2012 One month LIBOR rate	Mar. 31, 2012 Revolving Credit Facility	Dec. 31, 2011 Revolving Credit Facility	Mar. 31, 2012 Revolving Credit Facility Minimum	Mar. 31, 2012 Revolving Credit Facility Maximum	Mar. 31, 2012 Revolving Credit Facility Swing Line Loans	Mar. 31, 2012 Revolving Credit Facility Effective rates applicable to base rate loans Base Rate Minimum	Mar. 31, 2012 Revolving Credit Facility Effective rates applicable to base rate loans Base Rate Maximum	Mar. 31, 2012 Revolving Credit Facility Eurodollar borrowings LIBOR Minimum	Mar. 31, 2012 Revolving Credit Facility Eurodollar borrowings LIBOR Maximum	Dec. 31, 2011 Funded letter of credit facility	Mar. 31, 2012 Term Loan	Dec. 31, 2011 Term Loan	Mar. 31, 2012 Term Loan Base Rate Minimum	Mar. 31, 2012 Term Loan Base Rate Maximum	Mar. 31, 2012 Term Loan LIBOR	Mar. 31, 2012 Term Loan LIBOR Minimum	Mar. 31, 2012 Term Loan LIBOR Maximum	Mar. 31, 2012 Term Loan March 28, 2013	Mar. 31, 2012 6.375% Senior Notes Due 2022	Mar. 31, 2012 6.375% Senior Notes Due 2022 At any time prior to April 1, 2015	Mar. 31, 2012 6.375% Senior Notes Due 2022 At any time prior to April 1, 2017	Mar. 31, 2012 6.375% Senior Notes Due 2022 Maximum At any time prior to April 1, 2015	Mar. 31, 2012 Letters of credit	Dec. 31, 2011 Letters of credit	Mar. 31, 2012 Incremental Credit Facility	Mar. 31, 2012 3.25% Cash Convertible Senior Notes due 2014	Dec. 31, 2011 3.25% Cash Convertible Senior Notes due 2014	Mar. 23, 2012 1.00% Senior Convertible Debentures due 2027	Feb. 01, 2012 1.00% Senior Convertible Debentures due 2027	Mar. 31, 2012 1.00% Senior Convertible Debentures due 2027	Dec. 31, 2011 1.00% Senior Convertible Debentures due 2027
Schedule of Capitalization [Line Items]
Credit Facilities	$ 1,200,000,000								$ 900,000,000	$ 300,000,000			$ 50,000,000					$ 320,000,000	$ 300,000,000	$ 650,000,000											$ 900,000,000	$ 520,000,000
Debt carrying amount																			299,000,000	619,000,000							400,000,000							474,000,000	442,000,000				25,000,000	[1]
Revolving credit facility									275,000,000																						275,000,000
Loss on extinguishment of debt	(2,000,000)
Increase in additional capacity																																	500,000,000
Maximum leverage ratio	2.75
Term loan repayment premium																										1.00%
Excess cash flow requirement	Under certain circumstances, the 2012 Credit Facilities obligate us to apply 25% of our excess cash flow (as defined in the Credit Agreement) for each fiscal year commencing in 2013, as well as net cash proceeds from specified other sources, such as asset sales or insurance proceeds, to prepay the Term Loan, provided that this excess cash flow percentage shall be reduced to 0% in the event the leverage ratio is at or below 3.00:1.00.
Percentage of portion of excess cash to be used to repay borrowings under term loan based on measurement of leverage ratio	25.00%
Excess cash flow percentage	0.00%
Leverage ratio	3.00
Incremental rate added to the reference rate							0.50%	1.00%						1.25%	1.75%	2.00%	2.75%				1.75%	2.00%		2.75%	3.00%
Fronting fee																															0.125%
Unused commitment fee											0.375%	0.50%
LIBOR rate floor																							1.00%
Interest and fee terms	Borrowings under the 2012 Credit Facilities bear interest, at our option, at either a base rate or a Eurodollar rate plus an applicable margin determined by pricing grids, which are based on Covanta Energy’s leverage ratio. Base rate is defined as the higher of (i) the Federal Funds Effective Rate plus 0.50%, (ii) the rate the administrative agent announces from time to time as its per annum “prime rate” or (iii) the one-month LIBOR rate plus 1.00%. Eurodollar rate borrowings bear interest at the British Bankers’ Association LIBOR Rate, commonly referred to as “LIBOR”, for the interest period selected by us. Base rate borrowings under the Revolving Credit Facility shall bear interest at the base rate plus an applicable margin ranging from 1.25% to 1.75%. Eurodollar borrowings under the Revolving Credit Facility shall bear interest at LIBOR plus an applicable margin ranging from 2.00% to 2.75%. Fees for issuances of letters of credit include fronting fees equal to 0.125% per annum and a participation fee for the lenders equal to the applicable interest margin for LIBOR rate borrowings. We will incur an unused commitment fee ranging from 0.375% to 0.50% on the unused amount of commitments under the Revolving Credit Facility. The Term Loan bears interest, at our option, at either (i) the base rate plus an applicable margin ranging from 1.75% to 2.00%, or (ii) LIBOR plus an applicable margin ranging from 2.75% to 3.00%, subject to a LIBOR floor of 1.00%.
Line of credit facility guarantees and securitization description	The Credit Facilities are guaranteed by us and by certain of our subsidiaries. The subsidiaries that are party to the Credit Facilities agreed to secure all of the obligations under the Credit Facilities by granting, for the benefit of secured parties, a first priority lien on substantially all of their assets, to the extent permitted by existing contractual obligations, a pledge of substantially all of the capital stock of each of our domestic subsidiaries and 65% of substantially all the capital stock of each of our foreign subsidiaries which are directly owned, in each case to the extent not otherwise pledged.
Percentage of capital stock pledged for credit facilities					65.00%
Maximum leverage ratio	4.00
Minimum interest coverage ratio						3.00
Maturity date of debt instrument																											Oct. 01, 2022
Net proceeds from Notes offering																											392,000,000
Gross proceed from debt instrument offering																											400,000,000
Debt offering expense																											8,000,000
Description of debt instrument redemption																											At our option, the 6.375% Notes are subject to redemption at any time on or after April 1, 2017, in whole or in part, at the redemption prices set forth in the indenture, together with accrued and unpaid interest, if any, to the date of redemption. At any time prior to April 1, 2015, we may redeem up to 35% of the original principal amount of the 6.375% Notes with the proceeds of certain equity offerings at a redemption price of 106.375% of the principal amount of the 6.375% Notes, together with accrued and unpaid interest, if any, to the date of redemption. In addition, at any time prior to April 1, 2017, we may redeem some or all of the 6.375% Notes at a price equal to 100% of the principal amount, plus accrued and unpaid interest, plus a "make-whole" premium.
Percentage of Original amount that may be redeemed																														35.00%
Redemption price of principal amount																												106.375%	100.00%
Percentage of debt instrument repurchase price																											101.00%
Percentage of debt instrument to be repurchased																											100.00%
Conversion rate, numerator																																		60.3521
Conversion rate, denominator																																		1,000
Conversion price per share																																		$ 16.57
Conversion feature																																		We will not deliver common stock (or any other securities) upon conversion under any circumstances.
Redemption date																																						Feb. 01, 2012
Payment to repurchase Senior Convertible Debentures	25,000,000	6,000,000																																		2,000,000	23,000,000
Share based compensation granted			719,566	108,164
Common stock shares repurchased	280,831
Additional amounts of share repurchase authorization	100,000,000
Amount remaining under currently authorized share repurchase program	$ 145,000,000

[1] The remaining outstanding Debentures were redeemed at par during the first quarter of 2012. See additional information below under 1.00% Senior Convertible Debentures due 2027.