Retirement Benefits - Narrative (Details) (Primary U.S. retirement plan [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014
Primary U.S. retirement plan [Member]
Retirement Benefit Plan Remeasurements [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 22.5

Amount of employer's best estimate of contributions expected to be paid to the plan in the current remaining fiscal period.

No definition available.

Name:	us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration