Segment and Related Information (Details) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Reportable segments
Gross Operating Revenues	$ 3,871	$ 3,671	$ 7,434	$ 7,058
Intercompany Operating Revenues	(524)	(513)	(984)	(965)
Net Operating Revenues	3,347	3,158	6,450	6,093
Income from Operations	506	586	933	998
Eastern [Member]
Reportable segments
Gross Operating Revenues	800	774	1,504	1,459
Intercompany Operating Revenues	(136)	(140)	(248)	(253)
Net Operating Revenues	664	634	1,256	1,206
Income from Operations	141	143	261	252
Midwest [Member]
Reportable segments
Gross Operating Revenues	828	780	1,556	1,474
Intercompany Operating Revenues	(126)	(119)	(232)	(217)
Net Operating Revenues	702	661	1,324	1,257
Income from Operations	156	141	285	223
Southern [Member]
Reportable segments
Gross Operating Revenues	862	876	1,700	1,699
Intercompany Operating Revenues	(105)	(104)	(203)	(201)
Net Operating Revenues	757	772	1,497	1,498
Income from Operations	193	206	385	406
Western [Member]
Reportable segments
Gross Operating Revenues	825	799	1,615	1,563
Intercompany Operating Revenues	(114)	(112)	(222)	(215)
Net Operating Revenues	711	687	1,393	1,348
Income from Operations	142	141	282	270
Wheelabrator [Member]
Reportable segments
Gross Operating Revenues	226	217	436	423
Intercompany Operating Revenues	(30)	(29)	(61)	(60)
Net Operating Revenues	196	188	375	363
Income from Operations	42	47	55	83
Other [Member]
Reportable segments
Gross Operating Revenues	330	225	623	440
Intercompany Operating Revenues	(13)	(9)	(18)	(19)
Net Operating Revenues	317	216	605	421
Income from Operations	(21)	(26)	(35)	(55)
Operating Group Total [Member]
Reportable segments
Gross Operating Revenues	3,871	3,671	7,434	7,058
Intercompany Operating Revenues	(524)	(513)	(984)	(965)
Net Operating Revenues	3,347	3,158	6,450	6,093
Income from Operations	653	652	1,233	1,179
Corporate and Other [Member]
Reportable segments
Gross Operating Revenues	0	0	0	0
Intercompany Operating Revenues	0	0	0	0
Net Operating Revenues	0	0	0	0
Income from Operations	$ (147)	$ (66)	$ (300)	$ (181)

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Amount of total revenue for the reportable segment, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-Paragraph 27
-Subparagraph a, b, c

+ Details

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- Definition

Amount of revenue from external customers for the reportable segment. Must be disclosed if the amounts (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-Paragraph 27
-Subparagraph a

+ Details

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- Definition

The net result for the period of deducting operating expenses from operating revenues for the reportable segment.

+ Details

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- Definition

Amount of revenue from intercompany transactions. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

+ Details

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