Statements of Condensed Consolidated Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests in Consolidated Subsidiaries
Beginning Balance (in shares) at Dec. 31, 2015		152,554
Beginning Balance at Dec. 31, 2015	$ 8,028,042	$ 2,049,201	$ 2,982,212	$ 46,378	$ 2,950,251
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(22,278)		(261,025)		238,747
Net change in cash flow hedges:
Natural gas, net of tax benefit	(43,104)			(43,104)
Interest rate, net of tax expense	108			108
Pension and other post-retirement benefits liability adjustment, net of tax expense	9,917			9,917
Dividends	(14,966)		(14,966)
Stock-based compensation plans, net (in shares)		654
Stock-based compensation plans, net	26,372	$ 26,211			161
Distributions to noncontrolling interests	(137,719)				(137,719)
Issuance of common shares of EQT Corporation (in shares)		19,550
Issuance of common shares of EQT Corporation	1,225,999	$ 1,225,999
Issuance of common units of EQT Midstream Partners, LP	217,102				217,102
Changes in ownership of consolidated subsidiaries	(15,194)	$ 25,293			(40,487)
Ending Balance (in shares) at Sep. 30, 2016		172,758
Ending Balance at Sep. 30, 2016	9,274,279	$ 3,326,704	2,706,221	13,299	3,228,055
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	70,104
Net change in cash flow hedges:
Natural gas, net of tax benefit	(14,740)
Pension and other post-retirement benefits liability adjustment, net of tax expense	82
Ending Balance (in shares) at Sep. 30, 2016		172,758
Ending Balance at Sep. 30, 2016	9,274,279	$ 3,326,704	2,706,221	13,299	3,228,055
Beginning Balance (in shares) at Dec. 31, 2016		172,827
Beginning Balance at Dec. 31, 2016	9,119,247	$ 3,349,166	2,509,073	2,042	3,258,966
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	478,807		228,458		250,349
Net change in cash flow hedges:
Natural gas, net of tax benefit	(4,011)			(4,011)
Interest rate, net of tax expense	108			108
Pension and other post-retirement benefits liability adjustment, net of tax expense	230			230
Dividends	(15,620)		(15,620)
Stock-based compensation plans, net (in shares)		516
Stock-based compensation plans, net	18,414	$ 18,224			190
Distributions to noncontrolling interests	(172,498)				(172,498)
Ending Balance (in shares) at Sep. 30, 2017		173,343
Ending Balance at Sep. 30, 2017	9,424,677	$ 3,367,390	2,721,911	(1,631)	3,337,007
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	105,457
Net change in cash flow hedges:
Natural gas, net of tax benefit	(1,451)
Pension and other post-retirement benefits liability adjustment, net of tax expense	77
Ending Balance (in shares) at Sep. 30, 2017		173,343
Ending Balance at Sep. 30, 2017	$ 9,424,677	$ 3,367,390	$ 2,721,911	$ (1,631)	$ 3,337,007