Compensation Plans Net Profits Plan (Details) (Net Profits Plan [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Profits Plan [Member]
Costs recovered for payment to employees from net profit plan	100.00%
Percentage of future net cash flow received by participants from net profit plan	10.00%
Percentage Of future net cash flow received by participants from net profit plan increased yo	20.00%
Additional payment employees from net profit plan	200.00%
General and administrative expense	$ 13,734,000	$ 15,565,000		$ 19,326,000
Exploration expense	1,310,000	1,751,000		2,091,000
Total	15,044,000	17,316,000		21,417,000
Amount of cash payments related to divested properties	$ 10,300,000	$ 2,300,000	$ 6,300,000