Retirement Benefits - Information comparing plan asssets to obligatoins (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011 US Plans [Member]	Dec. 31, 2010 US Plans [Member]	Dec. 31, 2011 Non-US Plans [Member]	Dec. 31, 2009 Non-US Plans [Member]	Dec. 31, 2011 Pension plan [Member]	Dec. 31, 2010 Pension plan [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets [Abstract]
Fair value of plan assets	$ 685.4	$ 698.4	$ 117.5	$ 24.1	$ 802.9	$ 722.5
Accumulated benefit obligation	990.7	890.1	179.8	78.1	1,170.5	968.2
Projected benefit obligation	$ 990.7	$ 890.1	$ 206.4	$ 95.0	$ 1,197.1	$ 985.1

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

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If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References+ Details

- Definition

If aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References+ Details