Summary of Significant Accounting Policies Corrections to Consolidated Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Jun. 30, 2012
Net income (loss)	$ 6,514	$ (4,178)	$ 6,514	$ (4,178)
Depreciation and amortization	14,478	16,640
Provision for (recovery of) doubtful accounts	168	(963)
Deferred income taxes		0
Net gains on sales of assets	(50)	(3,202)
ESOP and share-based compensation expense	2,134	1,906
Realized and Unrealized Gains (Losses) on Derivatives And Investments, Net	1,949	7,038
Restricted cash	4,508	(1,987)
Purchases of short-term investments		(4,188)
Sales of short-term investments		3,417
Short-term investments		0
Increase (Decrease) in Accounts and Notes Receivable	(2,106)	(2,053)
Increase (Decrease) in Inventories	(5,608)	(2,404)
Increase (Decrease) in Income Taxes Receivable	251	289
Increase (Decrease) in Prepaid Expense and Other Assets	(85)	558
Accounts payable	2,361	3,885
Accrued payroll expenses and other current liabilities	(2,581)	(3,702)
Other long-term liabilities	(211)	(1,302)
Accrued postretirement benefits	(670)	351
Net Cash Provided by (Used in) Operating Activities	20,427	10,105
Previously Reported
Net income (loss)		(4,178)
Depreciation and amortization		16,640
Provision for (recovery of) doubtful accounts		(963)
Deferred income taxes		0
Net gains on sales of assets		(3,202)
ESOP and share-based compensation expense		1,906
Realized and Unrealized Gains (Losses) on Derivatives And Investments, Net		7,038
Restricted cash		(1,987)
Purchases of short-term investments		0
Sales of short-term investments		0
Short-term investments		(7,854)
Increase (Decrease) in Accounts and Notes Receivable		(2,053)
Increase (Decrease) in Inventories		(2,404)
Increase (Decrease) in Income Taxes Receivable		289
Increase (Decrease) in Prepaid Expense and Other Assets		558
Accounts payable		3,885
Accrued payroll expenses and other current liabilities		3,381
Other long-term liabilities		(1,302)
Accrued postretirement benefits		351
Net Cash Provided by (Used in) Operating Activities		$ 10,105