Commodity Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2017

Derivative [Line Items]

Summary of Fair Value and Classification of Derivative Instruments

The tables below summarize the fair value and classification of the Partnership’s derivative instruments, as well as the gross recognized derivative assets, liabilities and amounts offset in the consolidated balance sheets at December 31, 2017 and 2016: 

		As of December 31, 2017
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting			Net Carrying Value on Balance Sheet
		(in thousands)
Assets:
Current asset	Commodity derivative assets	$	10,713	$	(10,619	)	$	94
Long-term asset	Deferred charges and other long-term assets	1,392		(1,029		)	363
Total assets		$	12,105	$	(11,648	)	$	457
Liabilities:
Current liability	Commodity derivative liabilities	$	14,841	$	(10,619	)	$	4,222
Long-term liability	Commodity derivative liabilities	2,292		(1,029		)	1,263
Total liabilities		$	17,133	$	(11,648	)	$	5,485

		As of December 31, 2016
Classification	Balance Sheet Location	Gross Fair Value		Effect of Counterparty Netting			Net Carrying Value on Balance Sheet
		(in thousands)
Assets:
Current asset	Commodity derivative assets	$	3,879	$	(3,879	)	$	—
Long-term asset	Deferred charges and other long-term assets	—		—			—
Total assets		$	3,879	$	(3,879	)	$	—
Liabilities:
Current liability	Commodity derivative liabilities	$	20,116	$	(3,879	)	$	16,237
Long-term liability	Commodity derivative liabilities	482		—			482
Total liabilities		$	20,598	$	(3,879	)	$	16,719

Changes in Fair Value of Company's Commodity Derivative Instruments

Changes in the fair values of the Partnership’s derivative instruments (both assets and liabilities) are presented on a net basis in the accompanying consolidated statements of operations and consisted of the following for the periods presented:

	For the year ended December 31,
Derivatives not designated as hedging instruments	2017			2016			2015
	(in thousands)
Beginning fair value of commodity derivative instruments	$	(16,719	)	$	64,534		$	37,471
Gain (loss) on oil derivative instruments	(5,091		)	(15,998		)	57,681
Gain (loss) on natural gas derivative instruments	31,993			(20,466		)	32,607
Net cash received on settlements of oil derivative instruments	(10,901		)	(27,450		)	(41,786		)
Net cash received on settlements of natural gas derivative instruments	(4,310		)	(17,339		)	(21,439		)
Net change in fair value of commodity derivative instruments	11,691			(81,253		)	27,063
Ending fair value of commodity derivative instruments	$	(5,028	)	$	(16,719	)	$	64,534

Oil and Natural Gas

Derivative [Line Items]

Summary of Open Derivative Contracts

The Partnership had the following open derivative contracts for oil as of December 31, 2017:

	Volume (Bbl)	Weighted Average Price (per Bbl)		Range (per Bbl)
Period and Type of Contract				Low		High
Oil Swap Contracts:
2018
First quarter	729,000	$	54.36	$	52.09	$	57.15
Second quarter	736,000	54.33		52.09		56.75
Third quarter	744,000	54.35		51.85		55.87
Fourth quarter	749,000	54.24		51.85		55.87
2019
First quarter	165,000	$	53.58	$	52.82	$	54.02
Second quarter	165,000	53.58		52.82		54.02
Third quarter	165,000	53.58		52.82		54.02
Fourth quarter	165,000	53.58		52.82		54.02

The Partnership had the following open derivative contracts for natural gas as of December 31, 2017:

	Volume (MMBtu)	Weighted Average Price (per MMBtu)		Range (per MMBtu)
Period and Type of Contract				Low		High
Natural Gas Swap Contracts:
2018
First quarter	13,590,000	$	3.06	$	2.96	$	3.45
Second quarter	13,660,000	3.02		2.86		3.23
Third quarter	13,600,000	3.01		2.90		3.23
Fourth quarter	13,630,000	3.01		2.90		3.23
2019
First quarter	3,600,000	2.91		2.90		2.93
Second quarter	3,600,000	2.91		2.90		2.93
Third quarter	3,600,000	2.91		2.90		2.93
Fourth quarter	3,600,000	2.91		2.90		2.93