Interim Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Total operating revenues	$ 1,245,138	$ 1,050,046	$ 950,648	$ 1,312,036	$ 1,033,539	$ 597,718	$ 631,101	$ 828,662	$ 4,557,868	$ 3,091,020	$ 1,387,054
Operating (loss)	(570,691)	(147,451)	(114,650)	(1,950,332)	97,257	(6,380)	47,763	243,572	(2,783,124)	382,212	(755,028)
Amounts attributable to EQT Corporation:
(Loss) income from continuing operations	(598,062)	(127,347)	(76,978)	(1,578,533)	1,276,690	(6,238)	3,387	113,190	(2,380,920)	1,387,029	(531,493)
Income from discontinued operations, net of tax	(38,625)	87,654	94,784	(7,461)	3,381	29,578	37,739	50,802	136,352	121,500	78,510
Net (loss) income attributable to EQT Corporation	$ (636,687)	$ (39,693)	$ 17,806	$ (1,585,994)	$ 1,280,071	$ 23,340	$ 41,126	$ 163,992	$ (2,244,568)	$ 1,508,529	$ (452,983)
Basic:
(Loss) income from continuing operations (in dollars per share)	$ (2.35)	$ (0.49)	$ (0.29)	$ (5.96)	$ 5.83	$ (0.04)	$ 0.02	$ 0.66	$ (9.12)	$ 7.40	$ (3.18)
Income from discontinued operations (in dollars per share)	(0.15)	0.34	0.36	(0.03)	0.02	0.17	0.22	0.29	0.52	0.65	0.47
Net (loss) income (in dollars per share)	(2.50)	(0.15)	0.07	(5.99)	5.85	0.13	0.24	0.95	(8.60)	8.05	(2.71)
Diluted:
(Loss) income from continuing operations (in dollars per share)	(2.35)	(0.49)	(0.29)	(5.96)	5.81	(0.04)	0.02	0.66	(9.12)	7.39	(3.18)
Income from discontinued operations (in dollars per share)	(0.15)	0.34	0.36	(0.03)	0.02	0.17	0.22	0.29	0.52	0.65	0.47
Net (loss) income (in dollars per share)	$ (2.50)	$ (0.15)	$ 0.07	$ (5.99)	$ 5.83	$ 0.13	$ 0.24	$ 0.95	$ (8.60)	$ 8.04	$ (2.71)