Fair Value Measurements (Fair Value Hierarchy Table) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Current	$ 29,862	$ 5
Derivative Asset, Long-term	26,464	9,942
Total Derivative Assets	56,326	9,947
Derivative Liability, Current	(534)	(53,822)
Derivative Liability, Long-term	0	(3,413)
Total Derivative Liabilities	(534)	(57,235)
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Current	0	0
Derivative Asset, Long-term	0	0
Total Derivative Assets	0	0
Derivative Liability, Current	0	0
Derivative Liability, Long-term	0	0
Total Derivative Liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Current	18,609	5
Derivative Asset, Long-term	15,422	3,034
Total Derivative Assets	34,031	3,039
Derivative Liability, Current	(534)	(53,822)
Derivative Liability, Long-term	0	(3,214)
Total Derivative Liabilities	(534)	(57,036)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative Asset, Current	11,253	0
Derivative Asset, Long-term	11,042	6,908
Total Derivative Assets	22,295	6,908
Derivative Liability, Current	0	0
Derivative Liability, Long-term	0	(199)
Total Derivative Liabilities	$ 0	$ (199)