Derivative Instruments - Summary of Derivative Instrument Positions for Future Production Periods (Detail)	3 Months Ended
	Mar. 31, 2017 MMBTU $ / MMBTU $ / gal bbl gal
Natural Gas Swaps Production Period April 2017 – December 2017 [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	10,000
Weighted Average Price ($/MMBtu)	2.98
Natural Gas Swaps Production Period April 2017 – December 2017 [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	10,000
Weighted Average Price ($/MMBtu)	3.21
Propane Swaps Production Period April 2017 – December 2017 [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (Gal/d) | gal	84,000
Weighted Average Price ($/Gal) | $ / gal	0.60
Appalachia [Member] | Dominion Resources, Inc [Member] | Basis Swaps Production Period June 2017 – November 2017 [Member] | Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	40,000
Weighted Average Price ($/MMBtu)	(1.01)
Appalachia [Member] | Dominion Resources, Inc [Member] | Basis Swaps Production Period May 2017 – November 2017 [Member] | Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	40,000
Weighted Average Price ($/MMBtu)	(1.04)
Put Option [Member] | Natural Gas Collars Production Period April 2017 – December 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Floor ($/MMBtu)	2.75
Put Option [Member] | Natural Gas Collars Production Period April 2017 – December 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.90
Put Option [Member] | Natural Gas Collars Production Period January 2018 – December 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	40,000
Weighted Average Price, Floor ($/MMBtu)	2.75
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Floor ($/MMBtu)	2.75
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Floor ($/MMBtu)	2.25
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	50,000
Weighted Average Price, Floor ($/MMBtu)	3.00
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	50,000
Weighted Average Price, Floor ($/MMBtu)	2.25
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.75
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.25
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – March 2019 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Floor ($/MMBtu)	3.00
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – March 2019 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Floor ($/MMBtu)	2.20
Put Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – March 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Floor ($/MMBtu)	2.90
Put Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – March 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Floor ($/MMBtu)	2.40
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2018 – December 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Floor ($/MMBtu)	2.90
Put Option [Member] | Natural Gas Three-way Collars Production Period April 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Floor ($/MMBtu)	2.40
Put Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – December 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.90
Put Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.20
Put Option [Member] | Natural Gas Three-way Collars Production Period October 2017 – December 2018 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.90
Put Option [Member] | Natural Gas Three-way Collars Production Period October 2017 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Floor ($/MMBtu)	2.20
Put Option [Member] | Oil Swaps Production Period April 2017 – September 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Floor ($/MMBtu)	46.00
Volume (Bbls/d) | bbl	2,000
Put Option [Member] | Oil Swaps Production Period April 2017 – September 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Floor ($/MMBtu)	38.00
Volume (Bbls/d) | bbl	2,000
Put Option [Member] | Oil Swaps Production Period April 2017 – December 2017 [Member] | Purchase [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Floor ($/MMBtu)	46.00
Volume (Bbls/d) | bbl	2,000
Put Option [Member] | Oil Swaps Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Floor ($/MMBtu)	38.00
Volume (Bbls/d) | bbl	2,000
Call Option [Member] | Natural Gas Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Ceiling ($/MMBtu)	3.27
Call Option [Member] | Natural Gas Collars Production Period April 2017 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Ceiling ($/MMBtu)	3.25
Call Option [Member] | Natural Gas Collars Production Period January 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	40,000
Weighted Average Price, Ceiling ($/MMBtu)	3.28
Call Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Ceiling ($/MMBtu)	3.57
Call Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	50,000
Weighted Average Price, Ceiling ($/MMBtu)	3.40
Call Option [Member] | Natural Gas Call/Put Options Production Period January 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	40,000
Weighted Average Price ($/MMBtu)	3.75
Call Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Ceiling ($/MMBtu)	3.29
Call Option [Member] | Natural Gas Call/Put Options Production Period January 2019 – December 2019 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	10,000
Weighted Average Price ($/MMBtu)	4.75
Call Option [Member] | Natural Gas Three-way Collars Production Period April 2017 – March 2019 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	30,000
Weighted Average Price, Ceiling ($/MMBtu)	3.40
Call Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – March 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Ceiling ($/MMBtu)	3.75
Call Option [Member] | Natural Gas Three-way Collars Production Period April 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	60,000
Weighted Average Price, Ceiling ($/MMBtu)	3.25
Call Option [Member] | Natural Gas Three-way Collars Production Period January 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Ceiling ($/MMBtu)	3.50
Call Option [Member] | Natural Gas Three-way Collars Production Period October 2017 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price, Ceiling ($/MMBtu)	3.50
Call Option [Member] | Oil Swaps Production Period April 2017 – September 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Ceiling ($/MMBtu)	59.50
Volume (Bbls/d) | bbl	2,000
Call Option [Member] | Oil Swaps Production Period April 2017 – December 2017 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price, Ceiling ($/MMBtu)	60.00
Volume (Bbls/d) | bbl	2,000
Call Option [Member] | Oil Call/Put Options Production Period January 2018 – December 2018 [Member] | Sold [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Weighted Average Price ($/MMBtu)	50.00
Volume (Bbls/d) | bbl	1,000
TCO Columbia [Member] | Basis Swaps Production Period April 2017 – December 2017 [Member] | Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Volume (MMBtu/d) | MMBTU	20,000
Weighted Average Price ($/MMBtu)	(0.19)