Note 24 - Segment Information - Segment Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018
Revenues	$ 76,003,000	$ 63,623,000	$ 49,341,000	$ 60,867,000	$ 53,460,000	$ 44,501,000	$ 48,861,000	$ 47,697,000	$ 249,834,478	$ 194,519,345
Operating Income (Loss)	$ 5,616,000	$ 1,465,000	$ (1,620,000)	$ 2,604,000	$ 1,005,000	$ 552,000	$ 476,000	$ 2,213,000	8,064,705	4,245,523
Capital Expenditures									20,469,233	20,215,594
Depreciation, Amortization and Impairment									7,720,574	2,678,858
Corporate, Non-Segment [Member]
Revenues									1,975,748	2,657,837
Operating Income (Loss)									(6,899,256)	(3,535,774)
Capital Expenditures									209,043	1,104,089
Depreciation, Amortization and Impairment									585,247	480,487
Intersegment Eliminations [Member]
Revenues									(7,354,467)	(11,879,288)
Operating Income (Loss)									678,637	(1,261,045)
Depreciation, Amortization and Impairment									32,352	(5,298)
Overnight Air Cargo [Member]
Revenues									72,978,361	72,845,353
Overnight Air Cargo [Member] | Operating Segments [Member]
Revenues									72,978,361	72,845,353
Operating Income (Loss)									1,911,067	4,127,322
Capital Expenditures									57,806	40,668
Depreciation, Amortization and Impairment									82,102	110,810
Ground Equipment Sales [Member]
Revenues									47,152,125	50,004,507
Ground Equipment Sales [Member] | Operating Segments [Member]
Revenues									47,152,125	50,036,035
Operating Income (Loss)									3,419,786	3,840,907
Capital Expenditures									371,902	219,592
Depreciation, Amortization and Impairment									263,945	433,184
Ground Equipment Sales [Member] | Operating Segments [Member] | Domestic [Member]
Revenues									40,706,629	47,394,193
Ground Equipment Sales [Member] | Operating Segments [Member] | International [Member]
Revenues									6,445,496	2,641,842
Ground Support Services [Member]
Revenues									34,331,784	35,698,171
Ground Support Services [Member] | Operating Segments [Member]
Revenues									34,331,784	35,710,005
Operating Income (Loss)									(1,266,465)	(179,152)
Capital Expenditures									150,745	363,420
Depreciation, Amortization and Impairment									446,417	471,776
Printing Equipment and Maintenance [Member]
Revenues									654,617	6,144,403
Printing Equipment and Maintenance [Member] | Operating Segments [Member]
Revenues									669,307	6,386,882
Operating Income (Loss)									(1,388,434)	(749,846)
Capital Expenditures										181,895
Depreciation, Amortization and Impairment									9,085	13,135
Printing Equipment and Maintenance [Member] | Operating Segments [Member] | Domestic [Member]
Revenues									321,723	3,675,193
Printing Equipment and Maintenance [Member] | Operating Segments [Member] | International [Member]
Revenues									347,584	2,711,689
Commercial Jet Engines [Member] | Operating Segments [Member]
Revenues									100,081,620	38,762,521
Operating Income (Loss)									11,609,370	2,003,111
Capital Expenditures									19,679,737	18,305,930
Depreciation, Amortization and Impairment									6,301,426	1,174,764
Commercial Jet Engines [Member] | Operating Segments [Member] | Domestic [Member]
Revenues									68,856,992	25,324,231
Commercial Jet Engines [Member] | Operating Segments [Member] | International [Member]
Revenues									$ 31,224,628	$ 13,438,290