Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities:
Net loss attributable to NextDecade Corporation	$ (11,437)	$ (3,658)
Adjustment to reconcile net loss to net cash used in operating activities
Depreciation	47	48
Share-based compensation expense (forfeiture)	(2,372)	(3,729)
Loss on common stock warrant liabilities	6,304	2,038
Amortization of right-of-use assets	140	139
Amortization of other non-current assets	354	354
Changes in operating assets and liabilities:
Prepaid expenses	(194)	(169)
Accounts payable	114	(45)
Operating lease liabilities	(156)	(158)
Accrued expenses and other liabilities	(2,994)	1,390
Net cash used in operating activities	(10,194)	(3,790)
Investing activities:
Acquisition of property, plant and equipment	(1,314)	(2,384)
Acquisition of other non-current assets	(1,703)	(1,533)
Net cash used in investing activities	(3,017)	(3,917)
Financing activities:
Proceeds from sale of Series C Convertible Preferred Stock	10,500	24,500
Equity issuance costs	0	(54)
Preferred stock dividends	(19)	(13)
Shares repurchased related to share-based compensation	(464)	(44)
Net cash provided by financing activities	10,017	24,389
Net (decrease) increase in cash and cash equivalents	(3,194)	16,682
Cash and cash equivalents – beginning of period	25,552	22,608
Cash and cash equivalents – end of period	22,358	39,290
Non-cash investing activities:
Accounts payable for acquisition of property, plant and equipment	339	79
Accrued liabilities for acquisition of property, plant and equipment	839	395
Pipeline assets obtained in exchange for other non-current liabilities	0	84
Non-cash financing activities:
Paid-in-kind dividends on Convertible Preferred Stock	5,735	3,862
Accrued liabilities for equity issuance costs	50	0
Accretion of deemed dividends on Series A Convertible Preferred Stock	$ 0	$ 16