Income Taxes (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2015 Maximum Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Income Tax Expense (Benefit)	$ 221	$ 223	$ 673	$ 682
Effective income tax rate	31.80%	31.00%	30.10%	31.60%
Income Tax Expense Benefit, Period Increase (Decrease) due to tax settlement			(51)		(40)
Unrecognized Tax Benefits, Period Increase (Decrease) due to tax settlement			(59)
Unrecognized Tax Benefits, Interest on Income Taxes Accrued, Increase (Decrease) due to tax settlement	(12)		(12)
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 75		$ 75