Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2013 contract Unit	Dec. 31, 2012	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Number of daywork contracts			23
Number of contracts, daywork expiring in one year			22
Number of contracts, daywork expiring in two years			1
Book overdrafts	$ 7,000,000		$ 0	$ 7,000,000
Concentration of cash	40,400,000		52,100,000	40,400,000
Minimum depreciation percentage for idle drilling rigs			20.00%
Impairment of long-lived assets held-for-use	1,200,000		0	1,200,000	0
Goodwill impairment			0	0	0
Additions to goodwill			0	0	0
Goodwill deductible for tax purposes			3,900,000
Intangible asset impairment			0	0	0
Amortization on intangible assets			700,000	1,200,000	1,200,000
Accumulated amortization on intangible assets	17,300,000		18,000,000	17,300,000
Amortization to be recorded in 2014 on intangible assets			0
Directly related overhead costs capitalized	17,600,000		21,500,000	17,600,000	15,600,000
Average rates used for depreciation, depletion and amortization per Boe			13.32	14.70	15.06
Unproved properties not being amortized	521,659,000		545,588,000	521,659,000	185,632,000
Future discounted net cash flows discounted			10.00%
Impairment of oil and natural gas properties	167,700,000	115,900,000	0	283,606,000	0
Non-cash ceiling test write-down net of tax	104,400,000	72,100,000
Effects of cash flow hedges	29,800,000	32,500,000
Revenues from transactions with operating segments of same entity			64,300,000	49,600,000	52,200,000
Eliminated associated operating expense			46,900,000	34,100,000	32,600,000
Eliminated yielding			17,400,000	15,500,000	19,600,000
Number of partnerships			16
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for drilling of one well			20 days
Duration length of contracts			0 years 6 months
Insurance coverage			50,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of days for drilling of one well			90 days
Duration length of contracts			3 years
Insurance coverage			1,500,000
Under-Produced Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Natural gas balancing (MMcf)			5,200
Over-Produced Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Natural gas balancing (MMcf)			4,500
Natural Gas Balancing [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable			2,000,000
Liability recognized to under production			$ 3,800,000
Jul'12 - Dec'12 [Member]
Summary Of Significant Accounting Policies [Line Items]
Portion of future oil and gas production being hedged, as of the reporting period (MMBoe)		2.9
Jan'13 - Dec'13 [Member]
Summary Of Significant Accounting Policies [Line Items]
Portion of future oil and gas production being hedged, as of the reporting period (MMBoe)	6.9	4.5
Property, Plant and Equipment, Other Types [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, years			3 years
Property, Plant and Equipment, Other Types [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, years			15 years
Drilling Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, years			15 years