Retirement Benefits (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Contributions to U.S. non qualified and non-U.S. Pension Plan	$ 402
Expected fund in U.S. non pension plan	246
U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	42.00%
Actual asset allocation percentage of equity	60.00%
Actual asset allocation percentage of fixed income	40.00%
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation percentage for non-U.S. Plan assets	82.00%
U.K. Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Actual asset allocation percentage of equity	55.00%
Target asset allocation non-U.S. Plan, equities	53.00%
Target asset allocation non-U.S. Plan, fixed income	47.00%
Actual asset allocation percentage of fixed income	45.00%
Contributions to U.S. non qualified and non-U.S. Pension Plan	250
Canadian Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to U.S. non qualified and non-U.S. Pension Plan	$ 70
Equity Funds [Member] | U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation U.S. Plan, equities, prior period	58.00%