Retirement Benefit Plans (Schedule of benefit obligations in excess of plan assets) (Details) (Retirement Plans [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Retirement Plans [Member]
Accumulated benefit obligation	$ 416.6	$ 371.8
Fair value of plan assets	325.1	274.6
Projected benefit obligation	$ 416.6	$ 371.8

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.

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- 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