Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Operating segments information
Total assets	$ 9,682,252	$ 8,849,862
Operating segments
Operating segments information
Total assets	9,191,989	8,582,121
Operating segments | EQT Production
Operating segments information
Total assets	6,123,994	5,675,534
Operating segments | EQT Midstream
Operating segments information
Total assets	2,210,574	2,046,558
Operating segments | Distribution
Operating segments information
Total assets	857,421	860,029
Headquarters
Operating segments information
Total assets	$ 490,263	$ 267,741