Summary Of Significant Accounting Policies (Schedule of Inventory) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Schedule of Inventory [Line Items]
Materials and supplies inventories	$ 210,792,000	[1]	$ 258,962,000	[1]
Commodities	13,429,000		5,446,000
Inventory, Drilling, Noncurrent	(4,096,000)	[2]	(67,352,000)	[2]
Inventories	220,125,000		197,056,000
Net materials and supplies inventories reserves	$ 31,800,000		$ 4,600,000

[1] (a)As of December 31, 2013 and 2012, the Company's materials and supplies inventories were net of valuation reserve allowances of $31.8 million and $4.6 million, respectively. See Note D for additional information regarding inventory impairments.

[2] (b)Included in other noncurrent assets in the Company's accompanying consolidated balance sheet.