Other Comprehensive Income and Financial Instruments (Details 3) (USD $)	6 Months Ended
	Jun. 30, 2011 ShortTons
Collar Hedges Contract One [Member]
Summary of outstanding hedges
Inception Date	Dec. 08, 2010
Commencement Date	Jan. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	$ 80.00
Cap Strike Price Per Short Ton	180.00
Collar Hedges Contract Two [Member]
Summary of outstanding hedges
Inception Date	Dec. 08, 2010
Commencement Date	Jan. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	86.00
Cap Strike Price Per Short Ton	210.00
Collar Hedges Contract Three [Member]
Summary of outstanding hedges
Inception Date	Dec. 08, 2010
Commencement Date	Jan. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	81.00
Cap Strike Price Per Short Ton	190.00
Collar Hedges Contract Four [Member]
Summary of outstanding hedges
Inception Date	Dec. 08, 2010
Commencement Date	Jan. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	85.00
Cap Strike Price Per Short Ton	195.00
Collar Hedges Contract Five [Member]
Summary of outstanding hedges
Inception Date	Dec. 08, 2010
Commencement Date	Jan. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	87.00
Cap Strike Price Per Short Ton	195.00
Collar Hedges Contract Six [Member]
Summary of outstanding hedges
Inception Date	Jan. 19, 2011
Commencement Date	Feb. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,500
Floor Strike Price Per Short Ton	90.00
Cap Strike Price Per Short Ton	155.00
Collar Hedges Contract Seven [Member]
Summary of outstanding hedges
Inception Date	Jan. 19, 2011
Commencement Date	Feb. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,500
Floor Strike Price Per Short Ton	90.00
Cap Strike Price Per Short Ton	155.00
Collar Hedges Contract Eight [Member]
Summary of outstanding hedges
Inception Date	Apr. 15, 2011
Commencement Date	Jul. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	90
Cap Strike Price Per Short Ton	155.00
Collar Hedges Contract Nine [Member]
Summary of outstanding hedges
Inception Date	Apr. 15, 2011
Commencement Date	Jul. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	OCC
Notional Amount (in Gallons per Month)	2,000
Floor Strike Price Per Short Ton	90
Cap Strike Price Per Short Ton	155.00
Collar Hedges Contract Ten [Member]
Summary of outstanding hedges
Inception Date	Apr. 26, 2011
Commencement Date	Jul. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	ONP
Notional Amount (in Gallons per Month)	1,000
Floor Strike Price Per Short Ton	90
Cap Strike Price Per Short Ton	165
Collar Hedges Contract Eleven [Member]
Summary of outstanding hedges
Inception Date	Apr. 26, 2011
Commencement Date	Jul. 01, 2011
Termination Date	Dec. 31, 2012
Transaction Hedged	ONP
Notional Amount (in Gallons per Month)	1,000
Floor Strike Price Per Short Ton	90
Cap Strike Price Per Short Ton	$ 165