Retirement Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Contributions to U.S. non qualified and non-U.S. Pension Plan	$ 54
Non-U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of plan amendment on accumulated benefit obligation	147
Effect of plan amendment on funded status	(137)
Gain (loss) due to curtailments	65	0
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution during remainder of 2013	130
Gain (loss) due to curtailments	$ 65	$ 0
Equity Funds [Member] | United States Pension and Postretirement Benefit Plan of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	58.00%
Actual asset allocation percentage of equity	62.00%
Fixed Income Funds [Member] | United States Pension and Postretirement Benefit Plan of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	42.00%
Actual asset allocation percentage of equity	38.00%
United Kingdom [Member] | Equity Funds [Member] | Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	50.00%
Actual asset allocation percentage of equity	48.00%
United Kingdom [Member] | Fixed Income Funds [Member] | Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	50.00%
Actual asset allocation percentage of equity	52.00%
United Kingdom [Member] | Geographic Concentration Risk [Member] | Non-U.S. Plans [Member] | Non-U.S. Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Concentration risk percentage	82.00%