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Pension and Other Postretirement Benefit Plans | 6 Months Ended
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Jun. 30, 2013
Pension and Other Postretirement Benefit Plans [Abstract] |
Pension and Other Postretirement Benefit Plans [Text Block] | PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS
| Pension |  | Other Postretirement
Components of Net Periodic Benefit Expense | 2013 |  | 2012 |  | 2013 |  | 2012
Millions |  |  |  |  |  |  |
For the Quarter Ended June 30, |  |  |  |  |  |  |
Service Cost |  | $2.5 |  |  |  | $2.3 |  |  |  | $1.0 |  |  |  | $1.1 |
Interest Cost | 6.5 |  |  | 6.6 |  |  | 1.7 |  |  | 2.3 |
Expected Return on Plan Assets | (8.8 | ) |  | (8.9 | ) |  | (2.4 | ) |  | (2.5 | )
Amortization of Prior Service Costs | — |  |  | 0.1 |  |  | (0.7 | ) |  | (0.5 | )
Amortization of Net Loss | 5.4 |  |  | 4.4 |  |  | 0.4 |  |  | 1.9 |
Amortization of Transition Obligation | — |  |  | — |  |  | — |  |  | 0.1 |
Net Periodic Benefit Expense |  | $5.6 |  |  |  | $4.5 |  |  | — |  |  |  | $2.4 |
For the Six Months Ended June 30, |  |  |  |  |  |  |
Service Cost |  | $5.0 |  |  |  | $4.6 |  |  |  | $2.0 |  |  |  | $2.1 |
Interest Cost | 13.0 |  |  | 13.2 |  |  | 3.4 |  |  | 4.7 |
Expected Return on Plan Assets | (17.6 | ) |  | (17.7 | ) |  | (4.9 | ) |  | (5.0 | )
Amortization of Prior Service Costs | 0.1 |  |  | 0.2 |  |  | (1.3 | ) |  | (0.9 | )
Amortization of Net Loss | 10.7 |  |  | 8.7 |  |  | 0.8 |  |  | 3.8 |
Amortization of Transition Obligation | — |  |  | — |  |  | — |  |  | 0.1 |
Net Periodic Benefit Expense |  | $11.2 |  |  |  | $9.0 |  |  | — |  |  |  | $4.8 |
Employer Contributions. For the six months ended June 30, 2013, no contributions were made to our defined benefit pension plan (none for the six months ended June 30, 2012). For the six months ended June 30, 2013, we contributed $10.8 million to our other postretirement benefit plan (none for the six months ended June 30, 2012). We do not expect to contribute to our defined benefit pension plan in 2013, and we do not expect to make any additional contributions to our other postretirement benefit plan in 2013.

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- Definition The entire disclosure for pension and other postretirement benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -URI http://asc.fasb.org/topic&trid=2235017 + Details
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