Consolidated Variable Interest Entities - Amounts Included in Consolidated Operations and Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Operating revenues	$ 379,022	$ 556,726	$ 127,531	$ 545,069	$ 601,380	$ 583,978	$ 439,589	$ 714,815	$ 1,608,348	$ 2,339,762	$ 2,469,710
Operating expenses									1,894,673	1,776,623	1,650,461
Net (loss) income	$ (108,785)	$ 70,104	$ (180,807)	$ 88,425	$ (63,262)	$ 100,233	$ 63,747	$ 221,168	(131,063)	321,886	510,990
Net cash provided by operating activities									1,064,320	1,216,940	1,414,742
Net cash used in investing activities									(2,961,481)	(2,525,607)	(2,444,212)
Net cash (used in) provided by financing activities									1,399,469	1,832,470	1,261,258
Variable Interest Entity, Primary Beneficiary | EQGP and EQM
Variable Interest Entity [Line Items]
Operating revenues									735,614	632,936	489,218
Operating expenses									211,630	183,956	156,623
Other income (expenses)									11,010	(14,980)	(86,693)
Net (loss) income									534,994	434,000	245,902
Net cash provided by operating activities									535,357	488,329	324,837
Net cash used in investing activities									(732,033)	(1,043,822)	(524,437)
Net cash (used in) provided by financing activities									$ (103,828)	$ 735,712	$ 132,351