General and Summary of Significant Accounting Policies New Accounting Pronouncements Adopted (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,500
Other Noncurrent Liabilities [Member] | Accounting Standards Update 2013-11 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ (66)