Common Stock, Treasury Stock and Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic earnings per common share:
Net income (loss) attributable to EQT Corporation									$ 1,508,529	$ (452,983)	$ 85,171
Average common stock outstanding (in shares)									187,380,000	166,978,000	152,398,000
Basic earnings per common share (in dollars per share)	$ 5.85	$ 0.13	$ 0.24	$ 0.95	$ (1.11)	$ (0.05)	$ (1.55)	$ 0.04	$ 8.05	$ (2.71)	$ 0.56
Diluted earnings per common share:
Net income (loss) attributable to EQT Corporation									$ 1,508,529	$ (452,983)	$ 85,171
Stock options and awards (in shares)									347,000	0	541,000
Total (in shares)									187,727,000	166,978,000	152,939,000
Diluted earnings per common share (in dollars per share)	$ 5.83	$ 0.13	$ 0.24	$ 0.95	$ (1.11)	$ (0.05)	$ (1.55)	$ 0.04	$ 8.04	$ (2.71)	$ 0.56
Anti-dilutive securities (in shares)									429,785		291,700