Condensed Consolidated Statement of Comprehensive Income (parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Condensed Consolidated Statement of Comprehensive Income (parenthetical) [Abstract]
Adjustment to pension and other benefit plans tax impact	$ 1.4	$ 0.8	$ 2.9	$ 1.5
Unrealized gain or loss on investment tax impact	0	0.2	0.1	0.2
Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax	$ 0	$ 0	$ 0.1	$ 0

Tax effect of the gross appreciation or the gross loss, net of reclassification adjustment, in the value of the total unsold available-for-sale securities at the end of an accounting period.

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Tax effect on the accumulated change in the value of either the projected benefit obligation or plan assets resulting from experience different from that assumed or from a change in an actuarial assumption that has not been recognized in net periodic benefit cost.

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- Definition

Tax effect on the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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