Carrying amount of reserve for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs, which is expected to be paid within one year of the date of the statement of financial position.

+ References+ Details

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details

Commitments and Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended				3 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Aug. 25, 2011	Aug. 13, 2007	Jun. 30, 2013 Maximum [Member]	Jun. 30, 2013 Minimum [Member]	Aug. 25, 2011 past damages [Member]	Aug. 25, 2011 future damages [Member]
Purchase replacement coal				$ 100
Aggregate amount of past and future damages					377.0	228.0
Damages and interest awarded			104.1				13.8	90.3
Payments for Legal Settlements	15.6
Amount accrued	32.7	32.8
Amount accrued current portion	$ 3.6	$ 4.4