EARNINGS PER COMMON SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share
Net (Loss) Income from continuing operations	$ (5,844)	$ 1,763	$ (3,357)	$ (956)	$ 718	$ 581	$ (2,122)	$ 3,991	$ (8,394)	$ 3,168
Net Loss (Income) Attributable to Non-controlling Interests	230	335	433	115	(128)	(789)	(287)	(2,373)	1,113	(3,577)
Net loss from continuing operations attributable to Air T, Inc. Stockholders	$ (5,614)	$ 2,098	$ (2,924)	$ (841)	$ 590	$ (208)	$ (2,409)	$ 1,618	$ (7,281)	$ (409)
Loss from continuing operations per share (Note 22)
Basic (in dollars per share)	$ (1.96)	$ 0.73	$ (1.01)	$ (0.29)	$ 0.20	$ (0.07)	$ (0.80)	$ 0.72	$ (2.53)	$ (0.15)
Diluted (in dollars per share)	$ (1.96)	$ 0.73	$ (1.01)	$ (0.29)	$ 0.20	$ (0.07)	$ (0.80)	$ 0.72	$ (2.53)	$ (0.15)
Antidilutive shares Excluded from Computation of income (loss) per share (in shares)	8	0	5	5	0	6	0	0	6,000	0
Loss from discontinued operations, net of tax									$ 0	$ (114)
Gain on sale of discontinued operations, net of tax									4	8,179
Gain from discontinued operations attributable to Air T, Inc. stockholders	$ 0	$ 0	$ 4	$ 0	$ (2)	$ (222)	$ 8,124	$ 165	$ 4	$ 8,065
Income from discontinued operations per share:
Basic (in dollars per share)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (0.07)	$ 2.69	$ 0.07	$ 0	$ 2.89
Diluted (in dollars per share)	0	0	0	0	0	(0.07)	2.68	0.07	0	2.88
(Loss) Income per share:
Basic (in dollars per share)	(1.96)	0.73	(1.01)	(0.29)	0.20	(0.14)	1.89	0.79	(2.53)	2.74
Diluted (in dollars per share)	$ (1.96)	$ 0.73	$ (1.01)	$ (0.29)	$ 0.20	$ (0.14)	$ 1.88	$ 0.79	$ (2.53)	$ 2.73
Weighted Average Shares Outstanding:
Basic (in shares)									2,882,000	2,791,000
Diluted (in shares)									2,882,000	2,798,000
Continuing Operations
Loss from continuing operations per share (Note 22)
Antidilutive shares Excluded from Computation of income (loss) per share (in shares)	8	0	5	5	0	6	5	0	6,000	7,000
Discontinued Operations
Loss from continuing operations per share (Note 22)
Antidilutive shares Excluded from Computation of income (loss) per share (in shares)	0	0	0	0	7	6	0	0	0	0