Divestiture	9 Months Ended
Sep. 30, 2011
Divestiture [Abstract]
Divestiture	2. Divestiture In September 2010, we recorded a non-cash adjustment as an increase of operation and maintenance expense of approximately $21 million to write down net property, plant and equipment based on a Federal Energy Regulatory Committee (FERC) order related to the sale of the Natural Buttes facilities. In October 2010, we filed a request for rehearing and clarification of the FERC order and in October 2011, the FERC denied our request. For a further discussion of Natural Buttes, see our 2010 Annual Report on Form 10-K.

2. Divestiture

In September 2010, we recorded a non-cash adjustment as an increase of operation and maintenance expense of approximately $21 million to write down net property, plant and equipment based on a Federal Energy Regulatory Committee (FERC) order related to the sale of the Natural Buttes facilities. In October 2010, we filed a request for rehearing and clarification of the FERC order and in October 2011, the FERC denied our request. For a further discussion of Natural Buttes, see our 2010 Annual Report on Form 10-K.