BASIS OF PRESENTATION, CONSOLIDATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Property and equipment sold or disposed (Details)	3 Months Ended		6 Months Ended
	Sep. 30, 2019 USD ($) aircraft	Sep. 30, 2018 USD ($) aircraft	Sep. 30, 2019 USD ($) aircraft	Sep. 30, 2018 USD ($) aircraft
Property, Plant and Equipment [Line Items]
Number of aircraft sold or disposed of | aircraft	1	0	3	3
Proceeds from asset dispositions	$ 1,799,000	$ 688,000	$ 5,003,000	$ 8,462,000
Loss on disposal of assets	230,000	1,293,000	4,017,000	2,971,000
Impairment of property and equipment	42,022,000	104,939,000	42,022,000	104,939,000
H225 Aircraft
Property, Plant and Equipment [Line Items]
Impairment of property and equipment	$ 42,000,000	87,500,000	$ 42,000,000	87,500,000
Eastern Airways International Limited [Member]
Property, Plant and Equipment [Line Items]
Impairment of property and equipment		$ 17,500,000		$ 17,500,000