SEGMENT INFORMATION - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 65,604	$ 73,300	$ 50,693	$ 47,188	$ 67,329	$ 55,486	$ 40,867	$ 51,820	$ 236,785	$ 215,502
Income (Loss) from continuing operations, net of tax									7,291	9,331
Capital expenditures									37,149	20,319
Depreciation, amortization, and impairment									5,699	7,274
Overnight air cargo
Segment Reporting Information [Line Items]
Revenues									75,275	72,978
Ground equipment sales
Segment Reporting Information [Line Items]
Revenues									59,156	47,152
Printing equipment and maintenance
Segment Reporting Information [Line Items]
Revenues									306	655
Operating Segments | Overnight air cargo
Segment Reporting Information [Line Items]
Revenues									75,275	72,978
Income (Loss) from continuing operations, net of tax									709	1,911
Capital expenditures									299	58
Depreciation, amortization, and impairment									72	82
Operating Segments | Ground equipment sales
Segment Reporting Information [Line Items]
Revenues									59,156	47,152
Income (Loss) from continuing operations, net of tax									7,302	3,420
Capital expenditures									881	372
Depreciation, amortization, and impairment									279	264
Operating Segments | Ground equipment sales | Domestic
Segment Reporting Information [Line Items]
Revenues									54,108	40,707
Operating Segments | Ground equipment sales | International
Segment Reporting Information [Line Items]
Revenues									5,048	6,445
Operating Segments | Printing equipment and maintenance
Segment Reporting Information [Line Items]
Revenues									471	669
Income (Loss) from continuing operations, net of tax									(1,767)	(1,388)
Capital expenditures									0	0
Depreciation, amortization, and impairment									34	9
Operating Segments | Printing equipment and maintenance | Domestic
Segment Reporting Information [Line Items]
Revenues									200	322
Operating Segments | Printing equipment and maintenance | International
Segment Reporting Information [Line Items]
Revenues									271	347
Operating Segments | Commercial Jet Engines
Segment Reporting Information [Line Items]
Revenues									104,569	100,082
Income (Loss) from continuing operations, net of tax									7,977	11,609
Capital expenditures									34,873	19,680
Depreciation, amortization, and impairment									4,771	6,302
Operating Segments | Commercial Jet Engines | Domestic
Segment Reporting Information [Line Items]
Revenues									60,813	68,857
Operating Segments | Commercial Jet Engines | International
Segment Reporting Information [Line Items]
Revenues									43,756	31,225
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Revenues									2,264	1,976
Income (Loss) from continuing operations, net of tax									(7,771)	(6,899)
Capital expenditures									1,096	209
Depreciation, amortization, and impairment									558	585
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues									(4,950)	(7,355)
Income (Loss) from continuing operations, net of tax									841	678
Depreciation, amortization, and impairment									$ (15)	$ 32