Financial Information by Business Segment - Schedule of Segment Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Segment assets:
Total assets	$ 15,646,614	$ 15,472,922
Operating Segments
Segment assets:
Total assets	14,270,968	13,548,711
Operating Segments | EQT Production
Segment assets:
Total assets	11,577,963	10,923,824
Operating Segments | EQT Gathering
Segment assets:
Total assets	1,279,944	1,225,686
Operating Segments | EQT Transmission
Segment assets:
Total assets	1,413,061	1,399,201
Headquarters assets, including cash and short-term investments
Segment assets:
Total assets	$ 1,375,646	$ 1,924,211