|
Pension Plans and Other Postretirement Benefits (Details11) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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|---|---|---|---|
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Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | $ 2,220.0 | $ 2,232.7 | $ 2,237.4 |
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Other Postretirement Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 6.3 | 8.8 | 12.5 |
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Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
|
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 544.2 | 556.8 | |
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Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 1,335.6 | 1,382.1 | |
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Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 340.2 | 293.8 | |
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Equity Securities Us [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 601.1 | 513.7 | |
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Equity Securities Us [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 198.2 | 168.2 | |
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Equity Securities Us [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 402.9 | 345.5 | |
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Equity Securities Us [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Equity Securities Non Us [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 264.2 | 222.9 | |
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Equity Securities Non Us [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 27.0 | 21.6 | |
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Equity Securities Non Us [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 237.2 | 201.3 | |
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Equity Securities Non Us [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Equity Securities Ati Common Stock [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 89.7 | 141.2 | |
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Equity Securities Ati Common Stock [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 89.7 | 141.2 | |
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Equity Securities Ati Common Stock [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Equity Securities Ati Common Stock [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Fixed Income And Cash Equivalents [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 911.3 | 1,050.5 | |
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Fixed Income And Cash Equivalents [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 224.5 | 221.2 | |
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Fixed Income And Cash Equivalents [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 685.4 | 827.4 | |
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Fixed Income And Cash Equivalents [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 1.4 | 1.9 | |
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Private Equity Funds [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 85.5 | 80.6 | |
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Private Equity Funds [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Private Equity Funds [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
|
Private Equity Funds [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 85.5 | 80.6 | |
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Hedge Funds [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 148.9 | 121.9 | |
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Hedge Funds [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Hedge Funds [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
|
|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 0 | 0 | |
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Hedge Funds [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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|||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 148.9 | 121.9 | |
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Hedge Funds [Member] | Fair Value Inputs Level 3 [Member] | Other Postretirement Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 6.0 | ||
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Real Estate [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 119.3 | 101.9 | |
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Real Estate [Member] | Fair Value Inputs Level 1 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 4.8 | 4.6 | |
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Real Estate [Member] | Fair Value Inputs Level 2 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | 10.1 | 7.9 | |
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Real Estate [Member] | Fair Value Inputs Level 3 [Member] | Pension Benefits [Member]
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| Defined Benefit Plan Disclosure [Line Items] | |||
| Defined Benefit Plan Fair Value Of Plan Assets | $ 104.4 | $ 89.4 |