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Related Party Transactions - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2010
Administrative and Management Services [Member]
Related Party Transaction [Line Items]
Management fee expense			$ 15.6
Eclipse Resources Operating, LLC ("Eclipse Operating") [Member] \| Administrative and Management Services [Member]
Related Party Transaction [Line Items]
Total consideration		$ 0.1
President and Chief Executive Officer of Eclipse I, its Executive Vice President, Secretary, and General Counsel and its Executive Vice President and Chief Operating Officer [Member]
Related Party Transaction [Line Items]
Percentage of membership units owned by related party				33.00%
Chairman President And Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Flight charter services fees	$ 0.1	$ 0.3