Segment Information (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Operating segments information
Total assets	$ 8,802,484	$ 8,849,862
Reportable Segments
Operating segments information
Total assets	8,574,122	8,582,121
EQT Production
Operating segments information
Total assets	5,668,742	5,675,534
EQT Midstream
Operating segments information
Total assets	2,063,049	2,046,558
Distribution
Operating segments information
Total assets	842,331	860,029
Unallocated expenses
Operating segments information
Total assets	$ 228,362	$ 267,741