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Commitments and Contingencies - Central States, Southeast and Southwest Areas Pension Fund (Details Textual 6) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | 3 Months Ended | |
|---|---|---|---|---|
|
Mar. 31, 2013
PensionPlan
|
Dec. 31, 2012
|
Dec. 31, 2012
Daneville, Illinois and Dayton, Ohio Facilities [Member]
withdrawl_event
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Mar. 31, 2013
Michigan Facilities [Member]
withdrawl_event
|
|
| Commitments and Contingencies [Line Items] | ||||
| Withdrawl liability - Central States | $ 88.6 | $ 30.7 | $ 30.7 | $ 58.0 |
| Withdrawal liability, number of withdrawl events | 2 | 3 | ||
| Estimated additional liability on complete withdrawal from the Fund | $ 75 | |||
| Period of liability associated expenses | 20 years | |||
| Number of multi-employer pension plans (in number of plans) | 27 | |||
| Number of other multiemployer plans participated in (in number of plans) | 26 | |||
| Number of other critical or endangered multiemployer pension plans contributed to (in number of plans) | 20 |