Consolidated Statement of Stockholders' Equity and Convertible Preferred Stock (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Treasury Stock, Common and Preferred [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Series A Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2022	143,549	991
Balance at Dec. 31, 2022	$ 14	$ (4,587)	$ 289,084	$ (230,140)	$ 73,026	$ 73,408	$ 56,009	$ 0	$ 54,371
Share-based compensation	$ 0	$ 0	21,677	0	0	0	0	0	21,677
Restricted stock vesting (in shares)	3,901	0
Restricted stock vesting	$ 0	$ 0	558	0	0	0	0	0	558
Shares repurchased related to share-based compensation (in shares)	(1,194)	1,194
Shares repurchased related to share-based compensation	$ 0	$ (9,607)	0	0	0	0	0	0	(9,607)
Issuance of common stock, net (in shares)	50,736	0
Issuance of common stock, net	$ 6	$ 0	254,394	0	0	0	0	0	254,400
Rio Bravo Pipeline, LLC de-consolidation	0	0	0	629	0	0	0	0	629
Sale of equity in Intermediate Holdings	0	0	(14,424)	0	0	0	0	273,433	259,009
Preferred stock dividends	$ 0	$ 0	(20,484)	0	7,658	7,304	5,469	0	(20,484)
Preferred stock conversion (in shares)	59,542	0
Preferred stock conversion	$ 6	$ 0	222,868	0	(80,684)	(80,712)	(61,478)	0	222,874
Net income (loss) attributable to NextDecade Corporation	$ 0	$ 0	0	(32,996)	0	0	0	67,204	34,208
Balance (in shares) at Sep. 30, 2023	256,534	2,185
Balance at Sep. 30, 2023	$ 26	$ (14,194)	753,673	(262,507)	0	0	0	340,637	817,635
Balance at Dec. 31, 2022									54,371
Balance at Sep. 30, 2023									476,998
Balance (in shares) at Jun. 30, 2023	157,494	1,003
Balance at Jun. 30, 2023	$ 16	$ (4,657)	362,735	(377,776)	78,056	78,206	59,602	0	(19,682)
Share-based compensation	$ 0	$ 0	9,570	0	0	0	0	0	9,570
Restricted stock vesting (in shares)	3,806	0
Restricted stock vesting	$ 0	$ 0	558	0	0	0	0	0	558
Shares repurchased related to share-based compensation (in shares)	(1,182)	1,182
Shares repurchased related to share-based compensation	$ 0	$ (9,537)	0	0	0	0	0	0	(9,537)
Issuance of common stock, net (in shares)	36,874	0
Issuance of common stock, net	$ 4	$ 0	179,396	0	0	0	0	0	179,400
Rio Bravo Pipeline, LLC de-consolidation	0	0	0	629	0	0	0	0	629
Sale of equity in Intermediate Holdings	0	0	(14,424)	0	0	0	0	273,433	259,009
Preferred stock dividends	$ 0	$ 0	(7,030)	0	2,628	2,506	1,876	0	(7,030)
Preferred stock conversion (in shares)	59,542	0
Preferred stock conversion	$ 6	$ 0	222,868	0	(80,684)	(80,712)	(61,478)	0	222,874
Net income (loss) attributable to NextDecade Corporation	$ 0	$ 0	0	114,640	0	0	0	67,204	181,844
Balance (in shares) at Sep. 30, 2023	256,534	2,185
Balance at Sep. 30, 2023	$ 26	$ (14,194)	$ 753,673	$ (262,507)	$ 0	$ 0	$ 0	$ 340,637	817,635
Balance at Sep. 30, 2023									$ 476,998