Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues	$ 0	$ 0	$ 0	$ 0
Operating expenses
General and administrative expense	2,937	5,069	10,840	16,582
Land option and lease expense	240	423	678	1,281
Depreciation expense	43	65	136	146
Total operating expenses	3,220	5,557	11,654	18,009
Total operating loss	(3,220)	(5,557)	(11,654)	(18,009)
Other income (expense)
Gain (loss) on common stock warrant liabilities	4,442	(1,627)	(2,363)	6,147
Loss on redemption of investment securities	0	0	0	(412)
Interest income, net	0	7	2	241
Other	0	(1)	(1)	(17)
Total other income (expense)	4,442	(1,621)	(2,362)	5,959
Net income (loss) attributable to NextDecade Corporation	1,222	(7,178)	(14,016)	(12,050)
Preferred stock dividends	(5,264)	(3,613)	(13,015)	(10,565)
Deemed dividends on Series A Convertible Preferred Stock	(16)	(16)	(47)	(113)
Net loss attributable to common stockholders	$ (4,058)	$ (10,807)	$ (27,078)	$ (22,728)
Net loss per common share - basic and diluted (in dollars per share)	$ (0.03)	$ (0.09)	$ (0.23)	$ (0.19)
Weighted average shares outstanding - basic and diluted (in shares)	119,374	117,564	118,677	117,450