Summary of Significant Accounting Policies - Narrative (Details) a in Thousands				3 Months Ended	12 Months Ended
	Nov. 13, 2017 USD ($) a	Feb. 01, 2017 USD ($) a	May 15, 2015 shares	Jun. 30, 2016 USD ($)	Dec. 31, 2017 USD ($) a $ / Mcfe dry_hole segment shares	Dec. 31, 2016 USD ($) $ / Mcfe certificate_of_deposit segment	Dec. 31, 2015 USD ($) $ / Mcfe dry_hole	Dec. 31, 2014 USD ($)
Property, Plant and Equipment [Line Items]
Number of segments | segment					5	3
Maturity period (in months)					3 months
Number of CDs in denominations greater than $0.1 million held | certificate_of_deposit						2
Cash and cash equivalents					$ 147,315,000	$ 1,103,540,000	$ 1,601,232,000	$ 1,077,429,000
Unrealized holding gain (loss)					(2,600,000)	1,500,000
Trading securities					0	286,396,000
Oil and gas joint interest billing receivables					$ 149,300,000	1,100,000
Restricted cash						$ 75,000,000
Property acquisition term (in days)						180 days
Number of acres acquired (in acres) | a					304
Payment for acquisition					$ 818,957,000	$ 1,051,239,000	0
Losses for lower of cost or market adjustments					0	0	0
Internal costs					114,600,000	115,400,000	114,400,000
Interest costs capitalized					$ 20,500,000	$ 19,200,000	$ 35,800,000
Overall average rate of depletion | $ / Mcfe					1.04	1.06	1.18
Forward price curve period (in years)					5 years
Unproved property impairments					$ 0	$ 6,900,000	$ 19,700,000
Unproved oil and gas property impairments primarily as a result of lease expirations prior to drilling					7,600,000	8,700,000	37,400,000
Unproved properties					$ 5,016,299,000	1,698,826,000	$ 898,270,000
Number of exploratory dry holes | dry_hole					1		1
Capitalized exploratory well costs					$ 0	5,100,000.0
Asset and lease impairments and exploratory well costs					0		$ 4,200,000
Amortization of intangible assets					10,940,000	0	0
Amortization expense, year 1					82,900,000
Amortization expense, year 2					82,900,000
Amortization expense, year 3					77,500,000
Amortization expense, year 4					41,500,000
Amortization expense, year 5					41,500,000
Regulatory assets associated with deferred taxes					17,700,000	20,300,000
Deferred tax asset, provisional income tax expense (benefit)					11,300,000
AFUDC interest costs capitalized					800,000	2,400,000	1,600,000
AFUDC equity amounts capitalized					$ 5,100,000	19,400,000	6,300,000
Largest amount of benefit threshold, percentage (no greater than)					50.00%
Net loss of defined benefit pension plans, amortized from accumulated OCI, net of tax, into net periodic benefit cost						9,400,000
Amortization of transition asset						$ 5,100,000
Amortization period (in years)						16 years
Benefits paid				$ 5,400,000
Expense recognized related to defined contribution plan					$ 16,600,000	$ 16,000,000	15,700,000
Settlement of asset retirement obligations					143,600,000	66,200,000	7,000,000
Liabilities assumed						87,600,000
Adjustment to PPE					4,400,000	(27,700,000)	(114,800,000)
Capitalization of non-cash stock based compensation					9,000,000	16,600,000	25,200,000
Increase (decrease) in investment or payable for capital contributions						11,500,000
Rice Merger Agreement
Property, Plant and Equipment [Line Items]
Number of acres acquired (in acres) | a	270
Payment for acquisition	$ 1,299,407,000
Liabilities assumed					94,300,000
2017 Acquisitions
Property, Plant and Equipment [Line Items]
Liabilities assumed					10,000,000
2016 Acquisitions
Property, Plant and Equipment [Line Items]
Adjustment to PPE					14,300,000
Measurement adjustments					$ (14,300,000)
Midstream Management LLC
Property, Plant and Equipment [Line Items]
General partner interest	100.00%
RMPGP
Property, Plant and Equipment [Line Items]
General partner interest	100.00%
RMPGP | Rice Midstream Partners, LP
Property, Plant and Equipment [Line Items]
Limited partner interest					28.10%
RMPGP | Rice Midstream Partners, LP | Common Units
Property, Plant and Equipment [Line Items]
Common units owned (in shares) | shares					3,623
RMPGP | Rice Midstream Partners, LP | Limited Partner Subordinated
Property, Plant and Equipment [Line Items]
Common units owned (in shares) | shares					28,753,623
Strike Force Midstream Holdings LLC | Strike Force Midstream LLC
Property, Plant and Equipment [Line Items]
Limited partner interest					75.00%
Limited Partner Common
Property, Plant and Equipment [Line Items]
Limited partner interest			90.10%
Number of common units retained (in shares) | shares			239,715,000
Limited Partner Common | EQGP
Property, Plant and Equipment [Line Items]
Shares issued in IPO (in shares) | shares			26,450,000
Limited partner interest			9.90%
Limited Partner Common | EQGP | Affiliated Entity
Property, Plant and Equipment [Line Items]
Limited partner interest					26.60%
Common units owned (in shares) | shares					21,811,643
General Partner | EQGP
Property, Plant and Equipment [Line Items]
General partner interest					1.80%
General Partner | EQGP | Affiliated Entity
Property, Plant and Equipment [Line Items]
Number of general partner units (in shares) | shares					1,443,015
Customer Relationships
Property, Plant and Equipment [Line Items]
Intangible asset useful life					15 years
Noncompete Agreements
Property, Plant and Equipment [Line Items]
Intangible asset useful life					3 years
Unallocated Expenses
Property, Plant and Equipment [Line Items]
Asset and lease impairments and exploratory well costs						59,700,000
Minimum
Property, Plant and Equipment [Line Items]
Ownership percentage					20.00%
Maximum
Property, Plant and Equipment [Line Items]
Ownership percentage					50.00%
EQT Midstream | Building
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					35 years
EQT Midstream | Vehicles
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					5 years
EQT Midstream | Minimum | Gathering and Transmission Systems
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					20 years
EQT Midstream | Minimum | Office Equipment
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					3 years
EQT Midstream | Minimum | Computer Equipment
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					3 years
EQT Midstream | Minimum | Pipelines
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					10 years
EQT Midstream | Maximum | Gathering and Transmission Systems
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					65 years
EQT Midstream | Maximum | Office Equipment
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					7 years
EQT Midstream | Maximum | Computer Equipment
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					7 years
EQT Midstream | Maximum | Pipelines
Property, Plant and Equipment [Line Items]
Estimated service life (in years)					15 years
Permian Basin of Texas
Property, Plant and Equipment [Line Items]
Pretax impairment charges on proved oil and gas properties							94,300,000
Fair value							44,800,000
Carrying value of properties							345,000,000
Carrying value of undeveloped properties							300,000,000
Utica
Property, Plant and Equipment [Line Items]
Pretax impairment charges on proved oil and gas properties							4,300,000
Fair value							5,700,000
Impairment of Oil and Gas Properties
Property, Plant and Equipment [Line Items]
Pretax impairment charges on proved oil and gas properties							$ 98,600,000
Marion, Monongalia, and Wetzel Counties
Property, Plant and Equipment [Line Items]
Number of acres acquired (in acres) | a		14
Payment for acquisition		$ 130,000,000
Oil and Gas Receivable
Property, Plant and Equipment [Line Items]
Oil and gas receivable					$ 516,700,000	316,900,000
Certificates of Deposit
Property, Plant and Equipment [Line Items]
Cash and cash equivalents						$ 300,000,000