Financial Information by Business Segment (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 item	Mar. 31, 2013
Financial Information by Business Segment
Number of operating segments	2
Operating segments information
Revenues from external customers	$ 661,625,000	$ 415,883,000
Operating income	356,791,000	144,479,000
Reconciliation of operating income to income from continuing operations:
Other income	2,551,000	2,281,000
Interest expense	31,968,000	37,752,000
Income taxes	116,335,000	34,768,000
Income from continuing operations	211,039,000	74,240,000
Depreciation, depletion and amortization	152,111,000	143,036,000
Expenditure for segment assets	492,104,000	292,667,000
Non-cash capital expenditures	4,500,000	6,000,000
Operating segments | EQT Production
Operating segments information
Revenues from external customers	467,745,000	250,511,000
Operating income	277,205,000	74,097,000
Reconciliation of operating income to income from continuing operations:
Depreciation, depletion and amortization	131,239,000	124,909,000
Expenditure for segment assets	408,331,000	243,175,000
Expenditures for segment assets for property acquisitions	59,200,000	12,700,000
Operating segments | EQT Midstream
Operating segments information
Revenues from external customers	166,226,000	146,688,000
Operating income	83,069,000	74,214,000
Reconciliation of operating income to income from continuing operations:
Depreciation, depletion and amortization	21,009,000	18,219,000
Expenditure for segment assets	83,213,000	49,144,000
Less intersegment revenues, net
Operating segments information
Revenues from external customers	(16,975,000)	(17,057,000)
Less intersegment revenues, net | EQT Midstream
Reconciliation of operating income to income from continuing operations:
Intercompany eliminations for transmission and storage services		10,900,000
Third-party transportation costs
Operating segments information
Revenues from external customers	44,629,000	35,741,000
Unallocated expenses and Other
Operating segments information
Operating income	(3,483,000)	(3,832,000)
Reconciliation of operating income to income from continuing operations:
Depreciation, depletion and amortization	(137,000)	(92,000)
Expenditure for segment assets	$ 560,000	$ 348,000