Retirement Plans Schedule of Accumulated Benefit Obligation in Excess of Fair Value of Plan Assets (Details) (United Kingdom Subsidiary, UK Plan, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
United Kingdom Subsidiary \| UK Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 302,306	$ 265,061
Accumulated benefit obligation	302,306	265,061
Fair value of plan assets	$ 239,650	$ 204,080

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