Equity (Unrecognized Compensation Expense Related to Stock-Based Compensation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense	$ 25
Weighted Average Period	1 year 3 months 9 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense	61
Weighted Average Period	1 year 8 months 16 days
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense	$ 42
Weighted Average Period	1 year 10 months 18 days