Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 segment	Jun. 30, 2011
Operating segments information
Revenues from external customers	$ 337,804	$ 367,791	$ 787,764	$ 840,486
Operating income	81,404	153,170	234,700	373,582
Gain on dispositions			1,110	22,785
Reconciliation of operating income to net income:
Other income	5,249	18,046	9,930	24,850
Interest expense	40,629	33,287	81,881	66,139
Income taxes	14,578	50,175	59,268	122,284
Net income	31,446	87,754	103,481	210,009
Depreciation, depletion, and amortization	115,681	81,886	223,206	160,284
Expenditure for segment assets	392,733	374,098	662,320	637,526
Reportable segments number			3
EQT Production
Operating segments information
Revenues from external customers	158,649	196,810	354,045	369,852
Operating income	17,704	99,759	77,852	182,088
Gain on dispositions			1,110
Reconciliation of operating income to net income:
Depreciation, depletion, and amortization	94,405	61,899	180,972	119,733
Expenditure for segment assets	264,926	317,906	448,611	544,878
EQT Midstream
Operating segments information
Revenues from external customers	120,098	131,201	242,146	272,863
Operating income	59,750	52,243	115,886	141,661
Gain on dispositions				22,785
Reconciliation of operating income to net income:
Depreciation, depletion, and amortization	14,984	14,296	29,692	29,004
Expenditure for segment assets	119,925	46,500	199,563	75,605
Distribution
Operating segments information
Revenues from external customers	48,273	69,100	183,694	264,191
Operating income	6,376	8,928	43,146	62,295
Reconciliation of operating income to net income:
Depreciation, depletion, and amortization	6,287	5,923	12,530	11,880
Expenditure for segment assets	7,439	8,811	12,902	15,030
Other
Operating segments information
Revenues from external customers	10,784	(29,320)	7,879	(66,420)
Reconciliation of operating income to net income:
Depreciation, depletion, and amortization	5	(232)	12	(333)
Expenditure for segment assets	443	881	1,244	2,013
Unallocated expenses
Operating segments information
Operating income	$ (2,426)	$ (7,760)	$ (2,184)	$ (12,462)