Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		0 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 26, 2013 Oxford [Member]	Sep. 30, 2014 Oxford [Member] acre	Jun. 26, 2013 Oxford [Member] acre	Jun. 24, 2014 Eclipse Resources Operating, LLC ("Eclipse Operating") [Member]	Sep. 30, 2014 Eclipse Resources Operating, LLC ("Eclipse Operating") [Member]	Sep. 30, 2013 Pro Forma Financial Information [Member]
Business Acquisition [Line Items]
Total consideration								$ 100,000	$ 100,000
Recognized gain on bargain purchase			1,585,000					1,600,000
Acquired percentage of outstanding equity interests							100.00%
Area of leasehold property held						46,549	181,000
Aggregate purchase price					652,500,000
Escrow withheld from initial purchase price							32,500,000
Depletion, depreciation, amortization and accretion expense	29,983,000	2,462,000	51,967,000	3,445,000						7,000,000
Amortization of financing costs			1,314,000	647,000						400,000
Amortization of debt discount			1,711,000							600,000
Interest expense										$ 10,300,000