XML 1049 R77.htm IDEA: XBRL DOCUMENT

Asset Retirement Obligations (Details) (ARIZONA PUBLIC SERVICE COMPANY, USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Apr. 21, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008
ARIZONA PUBLIC SERVICE COMPANY
Asset Retirement Obligations
License extension approved by the NRC	20 years			20 years
Change in asset retirement obligations
Asset retirement obligations at the beginning of year		$ 280	$ 329
Changes attributable to:
Accretion expense		19	19
Estimated cash flow revisions		58	(68)
Asset retirement obligations at the end of year		$ 357	$ 280

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References+ Details

- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References+ Details