Fair Value of Financial Instruments (Assets Measured at Fair Value on a Non-Recurring Basis) (Details) (USD $)	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Asset	$ 15,100
Derivative, Fair Value, Total	15,100
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Asset	15,100
Derivative, Fair Value, Total	15,100
Natural Gas Put Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Asset	15,100
Derivative, Fair Value, Total	15,100	[1]
Natural Gas Put Options [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Asset	$ 15,100

[1] Fair value based on forward NYMEX natural gas prices, as applicable.