Financial Information by Business Segment - Schedule of Depreciation, Amortization, and Expenditures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Depreciation, depletion and amortization:
Depreciation, depletion and amortization	$ 246,560	$ 237,088	$ 719,295	$ 682,948
Expenditures for segment assets:
Expenditures for segment assets	522,299	793,879	2,081,986	1,606,854
Payments to acquire businesses, gross			818,957	412,348
Operating Segments | EQT Production
Depreciation, depletion and amortization:
Depreciation, depletion and amortization	224,103	220,768	654,411	635,253
Expenditures for segment assets:
Expenditures for segment assets	449,303	622,856	1,850,482	1,094,747
Consideration transferred	52,100	30,100	147,000	98,200
Payments to acquire businesses, gross	7,800	412,300	819,000	412,300
Capital expenditures incurred but not yet paid			7,500	6,200
Operating Segments | EQT Gathering
Depreciation, depletion and amortization:
Depreciation, depletion and amortization	9,983	7,663	28,398	22,520
Expenditures for segment assets:
Expenditures for segment assets	48,182	88,390	150,728	247,755
Operating Segments | EQT Transmission
Depreciation, depletion and amortization:
Depreciation, depletion and amortization	12,261	6,976	35,793	20,657
Expenditures for segment assets:
Expenditures for segment assets	22,312	77,940	73,679	253,957
Other
Depreciation, depletion and amortization:
Depreciation, depletion and amortization	213	1,681	693	4,518
Expenditures for segment assets:
Expenditures for segment assets	$ 2,502	$ 4,693	$ 7,097	$ 10,395