Employee Benefit Plans Accumulated Benefit Obligations (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Accumulated benefit obligation for all defined benefit plans	$ 392,200,000	$ 329,300,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Projected benefit obligation	437,980,000	323,918,000
Accumulated benefit obligation	392,182,000	285,590,000
Fair value of plan assets	$ 295,655,000	$ 255,728,000

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

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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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- Definition

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.

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