Earnings Per Share and Equity - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Dec. 31, 2014
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Treasury Stock, Shares held	35,000,000				35,000,000
Treasury Stock, Value	2,327				$ 2,327
Employee Stock Option [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Stock options not included in the calculation of diluted common shares outstanding	15,000,000	16,000,000	18,000,000	20,000,000