Segment Information - Segment Data (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	$ 50,693	$ 40,867	$ 97,881	$ 92,687
Overnight Air Cargo	466	(879)	1,465	1,812
Ground Equipment Sales	16,368	19,506	17,794	19,912
Printing Equipment and Maintenance	1,702	1,707	3,649	3,078
Corporate and other
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	542	189	1,141	365
Overnight Air Cargo	(1,902)	(1,935)	(3,860)	(3,666)
Ground Equipment Sales	51	34	72	111
Printing Equipment and Maintenance	137	151	277	296
Intercompany
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	(486)	(15)	(1,103)	(18)
Overnight Air Cargo	119	0	139	0
Printing Equipment and Maintenance	0	(1)	(3)	(3)
Air Cargo
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	19,745	17,064	38,064	34,705
Air Cargo | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	19,745	17,064	38,065	34,705
Overnight Air Cargo	216	197	264	1,253
Ground Equipment Sales	26	29	56	34
Printing Equipment and Maintenance	19	21	37	44
Ground equipment sales
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	12,741	12,838	24,991	19,224
Ground equipment sales | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	12,741	12,846	24,990	19,233
Overnight Air Cargo	1,221	697	2,568	1,091
Ground Equipment Sales	286	156	10	296
Printing Equipment and Maintenance	63	65	116	157
Ground equipment sales | Operating Segments | Domestic
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	12,102	11,070	22,960	16,362
Ground equipment sales | Operating Segments | International
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	639	1,776	2,030	2,871
Printing equipment and maintenance
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	249	139	313	439
Printing equipment and maintenance | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	249	140	317	439
Overnight Air Cargo	(381)	(413)	(837)	(654)
Ground Equipment Sales	0	0	0	0
Printing Equipment and Maintenance	27	15	30	30
Printing equipment and maintenance | Operating Segments | Domestic
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	175	3	197	194
Printing equipment and maintenance | Operating Segments | International
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	74	137	120	245
Commercial Jet Engines and Parts | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	17,902	10,643	34,471	37,963
Overnight Air Cargo	1,193	575	3,191	3,788
Ground Equipment Sales	16,005	19,287	17,656	19,471
Printing Equipment and Maintenance	1,456	1,456	3,192	2,554
Commercial Jet Engines and Parts | Operating Segments | Domestic
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	6,203	5,341	14,631	27,659
Commercial Jet Engines and Parts | Operating Segments | International
Segment Reporting Information [Line Items]
Operating Revenues by Segment:	$ 11,699	$ 5,302	$ 19,840	$ 10,304