Contingencies and Legacy Environmental Commitments (Tables)

3 Months Ended

Jun. 30, 2013

Commitments And Contingencies Disclosure [Abstract]

Schedule of Environmental Activity

The environmental activity is summarized as follows:

Balance at March 31, 2013	$	12,684
Environmental costs incurred		(324	)
Interest accretion		90
Reduction of environmental reserve-Wyoming Illinois		(1,207	)
Balance at June 30, 2013	$	11,243