XML 46 R25.htm IDEA: XBRL DOCUMENT

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2013
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events During the third quarter of 2013, the Company approved a plan to freeze pension benefits for certain NACoal unconsolidated mines' employees effective January 1, 2014. Affected employees will earn benefits under the Company's defined contribution retirement plans. The Company has not yet determined the estimated curtailment gain or loss associated with freezing the pension benefits but does not expect the curtailment gain or loss to have a significant impact on the Company's future financial position, results of operations or cash flows.