Summary of Significant Accounting Policies - Schedule of Regulated Net Property, Plant and Equipment (Details) - EQT Transmission and Storage - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant & equipment	$ 1,675,433	$ 1,356,206
Accumulated depreciation and amortization	(234,336)	(193,349)
Net property, plant & equipment	$ 1,441,097	$ 1,162,857