Equity (Compensation Expense Related to Stock-Based Compensation - Related to Phantom Stock-Based Awards) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	$ 175	$ 168	$ 144
Income tax benefits	61	59	50
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	39	61	58
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	91	80	68
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense	$ 45	$ 27	$ 18