Note 2 - Revenue Recognition - Disaggregation of Revenues (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues	$ 49,340,777	$ 48,861,490	$ 110,208,246	$ 96,558,863
Overnight Air Cargo [Member]
Revenues
Revenues	76,066		100,240
Revenues	17,064,600	18,081,073	34,705,258	34,823,248
Overnight Air Cargo [Member] | Product [Member]
Revenues	5,003,482		10,523,093
Overnight Air Cargo [Member] | Service [Member]
Revenues	11,985,052		24,081,926
Ground Equipment Sales [Member]
Revenues	15,357		46,359
Revenues	227,847		311,930
Revenues	12,838,796	15,516,109	19,223,577	21,465,765
Ground Equipment Sales [Member] | Product [Member]
Revenues	12,447,475		18,616,578
Ground Equipment Sales [Member] | Service [Member]
Revenues	148,118		248,710
Ground Support Services [Member]
Revenues
Revenues			19,795
Revenues	8,474,037	8,801,326	17,521,677	17,914,399
Ground Support Services [Member] | Product [Member]
Revenues	2,293,684		4,716,265
Ground Support Services [Member] | Service [Member]
Revenues	6,180,353		12,785,618
Commercial Jet Engines Inventory [Member]
Revenues	1,825,861		3,027,372
Revenues	109,995		233,719
Revenues	10,642,791	5,125,244	37,962,966	17,850,585
Commercial Jet Engines Inventory [Member] | Product [Member]
Revenues	7,379,607		32,408,721
Commercial Jet Engines Inventory [Member] | Service [Member]
Revenues	1,327,328		2,293,154
Printing Equipment and Maintenance [Member]
Revenues
Revenues	5,414		9,937
Revenues	139,945	1,302,922	438,768	4,434,303
Printing Equipment and Maintenance [Member] | Product [Member]
Revenues	122,238		408,880
Printing Equipment and Maintenance [Member] | Service [Member]
Revenues	12,293		19,951
Corporate Segment [Member]
Revenues	32,182		72,249
Revenues	131,950		267,275
Revenues	180,608	$ 34,816	356,000	$ 70,563
Corporate Segment [Member] | Product [Member]
Revenues
Corporate Segment [Member] | Service [Member]
Revenues	$ 16,475		$ 16,475