Schedule of Contractual Obligations (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Loss Contingencies [Line Items]
Contractual Obligation	$ 62,227
Contractual Obligation, Due in Next Twelve Months	53,870
Contractual Obligation, Due in Second and Third Year	990
Contractual Obligation, Due in Fourth and Fifth Year	346
Contractual Obligation, Due after Fifth Year	7,021
Purchase Obligation	28,022
Purchase Obligation, Due in Next Twelve Months	27,696
Purchase Obligation, Due in Second and Third Year	235
Purchase Obligation, Due in Fourth and Fifth Year	91
Purchase Obligation, Due after Fifth Year	0
Long-term Debt	22,291
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	22,291
Long-term Debt, Maturing in Years Two and Three	0
Long-term Debt, Maturing in Years Four and Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	0
Asset Retirement Obligation	4,953
Asset Retirement Obligation, Due in Next Twelve Months	0
Asset Retirement Obligation, Due in Second and Third Year	390
Asset Retirement Obligation, Due in Fourth and Fifth Year	33
Asset Retirement Obligation, Due after Fifth Year	4,530
Operating Leases, Future Minimum Payments Due	4,037
Operating Leases, Future Minimum Payments Due, Next Twelve Months	959
Operating Leases, Future Minimum Payments, Due in Two and Three Years	365
Operating Leases, Future Minimum Payments, Due in Four and Five Years	222
Operating Leases, Future Minimum Payments, Due Thereafter	2,491
Capital Leases, Future Minimum Payments Due	2,924
Capital Leases, Future Minimum Payments Due, Next Twelve Months	2,924
Capital Leases, Future Minimum Payments Due in Two and Three Years	0
Capital Leases, Future Minimum Payments Due in Four and Five Years	0
Capital Leases, Future Minimum Payments Due Thereafter	$ 0