Income Taxes	3 Months Ended
Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On September 13, 2013, the U.S. Treasury Department released final income tax regulations on the deduction and capitalization of expenditures related to tangible property. These final regulations apply to tax years beginning on or after January 1, 2014. Several of the provisions within the regulations require a tax accounting method change to be filed with the IRS prior to September 15, 2015, resulting in a tax-effected cumulative effect adjustment of approximately $82 million. The anticipated impact of these final regulations were accounted for in the Condensed Consolidated Balance Sheets as of December 31, 2014. Net income associated with the Palo Verde sale leaseback variable interest entities is not subject to tax (see Note 6). As a result, there is no income tax expense associated with the VIEs recorded on the Condensed Consolidated Statements of Income. As of March 31, 2015, the tax year ended December 31, 2011 and all subsequent tax years remain subject to examination by the IRS. With few exceptions, we are no longer subject to state income tax examinations by tax authorities for years before 2009.

Income Taxes

3 Months Ended

Mar. 31, 2015

On September 13, 2013, the U.S. Treasury Department released final income tax regulations on the deduction and capitalization of expenditures related to tangible property. These final regulations apply to tax years beginning on or after January 1, 2014. Several of the provisions within the regulations require a tax accounting method change to be filed with the IRS prior to September 15, 2015, resulting in a tax-effected cumulative effect adjustment of approximately $82 million. The anticipated impact of these final regulations were accounted for in the Condensed Consolidated Balance Sheets as of December 31, 2014.

Net income associated with the Palo Verde sale leaseback variable interest entities is not subject to tax (see Note 6). As a result, there is no income tax expense associated with the VIEs recorded on the Condensed Consolidated Statements of Income.

As of March 31, 2015, the tax year ended December 31, 2011 and all subsequent tax years remain subject to examination by the IRS. With few exceptions, we are no longer subject to state income tax examinations by tax authorities for years before 2009.