Share-Based Compensation Plans - Value Driver Award Programs - Additional Information (Details) - Value Driver Performance Programs	12 Months Ended
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vested at end of year one	50.00%
Award vested at end of year two	50.00%
Award requisite service period	1 year

This element represents the percentage of the stock-based award which will vest at the end of year one.

No definition available.

Name:	eqt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAtEndOfOneYearInPercentage
Namespace Prefix:	eqt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the percentage of the stock-based award which will vest at the end of year two.

+ References

No definition available.

+ Details

Name:	eqt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedAtEndOfTwoYearInPercentage
Namespace Prefix:	eqt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=eqt_VDPSUProgramsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: