Acquisitions (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Segment Operations	Jun. 30, 2011	Mar. 31, 2012 Oil and Gas [Member]	Jun. 30, 2012 Oakleaf [Member]	Jun. 30, 2012 Oakleaf [Member]	Dec. 31, 2011 Oakleaf [Member]	Dec. 31, 2010 Oakleaf [Member]	Jul. 28, 2011 Oakleaf [Member]
Business Acquisition [Line Items]
Acquisition cost of acquired entity						$ 432	$ 432	$ 432		$ 432
Cash received in acquisition										4
Operating revenues	3,459	3,347	6,754	6,450					580
Acquisition-related costs classified as Selling, general and administrative expenses								1
Revenues recognized by acquiree post the acquisition date						147	295
Net losses recognized by acquiree post the acquisition date						4	4
Purchase price allocation to goodwill						328	328	327
Total consideration, net of cash acquired, for business acquisition			$ 154	$ 157	$ 94
Business Combinations (Textual) [Abstract]
Number of collection and recycling operations acquired			16
Number of geographic segments			4