Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis

The financial instrument measured at fair value on a recurring basis is summarized below:

	Fair Value Measurements at December 31, 2018						Fair Value Measurements at December 31, 2017
Description	Level 1		Level 2		Level 3		Level 1		Level 2			Level 3
Gas Derivatives	$	—	$	99,456	$	—	$	—	$	59,949		$	—
Put Option	$	—	$	—	$	—	$	—	$	(3,500	)	$	—

Fair Value, by Balance Sheet Grouping

The carrying amounts and fair values of financial instruments for which the fair value option was not elected are as follows:

	December 31, 2018				December 31, 2017
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Cash and Cash Equivalents	$	17,198	$	17,198	$	509,167	$	509,167
Long-Term Debt (Excluding Debt Issuance Costs)	$	2,387,001	$	2,290,537	$	2,204,825	$	2,281,282