Compensation Plans Non Stock-based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Cash Bonus Plan [Member]
Cash Paid in Current Period for Bonus Compensation			$ 41,700,000	$ 16,000,000
Accrued Cash Bonus Plan Expense	6,200,000	5,800,000	19,000,000	16,700,000
Net Profits Plan [Member]
General and administrative expense	2,487,000	4,302,000	7,451,000	11,531,000
Exploration expense	162,000	329,000	644,000	1,026,000
Total	$ 2,649,000	$ 4,631,000	$ 8,095,000	$ 12,557,000