Financial Information by Business Segment - Schedule of Revenue from External Customers and Operating Income (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)
Operating segments information
Number of operating segments | segment				2
Revenues from external customers		$ 433,174	$ 526,168	$ 1,141,947	$ 1,187,793
Operating income		33,034	224,771	347,793	581,562
Reconciliation of operating income to income from continuing operations:
Total operating income		33,034	224,771	347,793	581,562
Other income		2,689	2,579	3,628	5,130
Interest expense		36,833	31,873	74,049	63,841
Income tax (benefit) expense		(64,857)	59,089	(7,543)	175,424
Income from continuing operations		63,747	136,388	284,915	347,427
Gain on sale / exchanges of assets				0	37,749
EQT Production
Reconciliation of operating income to income from continuing operations:
Gain on sale / exchanges of assets			31,000		31,000
EQT Midstream
Reconciliation of operating income to income from continuing operations:
Gain on sale / exchanges of assets			6,800		6,800
Operating Segments | EQT Production
Operating segments information
Revenues from external customers		243,587	373,532	745,781	885,906
Operating income	[1]	(66,886)	144,689	118,957	421,894
Reconciliation of operating income to income from continuing operations:
Total operating income	[1]	(66,886)	144,689	118,957	421,894
Operating Segments | EQT Midstream
Operating segments information
Revenues from external customers		192,430	162,345	400,656	328,571
Operating income	[1]	108,192	88,527	237,931	171,596
Reconciliation of operating income to income from continuing operations:
Total operating income	[1]	108,192	88,527	237,931	171,596
Less intersegment revenues, net
Operating segments information
Revenues from external customers	[2]	(2,843)	(9,709)	(4,490)	(26,684)
Unallocated expenses
Operating segments information
Operating income	[3]	(8,272)	(8,445)	(9,095)	(11,928)
Reconciliation of operating income to income from continuing operations:
Total operating income	[3]	$ (8,272)	$ (8,445)	$ (9,095)	$ (11,928)

[1] Gains on sales / exchanges of assets of $31.0 million and $6.8 million are included in EQT Production and EQT Midstream operating income, respectively, for the three and six months ended June 30, 2014.

[2] Eliminates intercompany natural gas sales from EQT Production to EQT Midstream.

[3] Unallocated expenses consist primarily of incentive compensation expense and administrative costs.