VARIABLE INTEREST ENTITIES AND OTHER INVESTMENTS IN SIGNIFICANT AFFILIATES Other Significant Affiliates - Unconsoildated Tables (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated affiliates	$ 126,170	$ 210,162
Cost Method Investment Dividends Or Distributions	2,518	2,068	$ 2,068
Income (Loss) from Equity Method Investments	4,220	4,877	(1,807)
Income (Loss) from Subsidiaries, before Tax	6,738	6,945	261
Proceeds from Equity Method Investment, Distribution	400	400	800
Equity Method Investment, Summarized Financial Information [Abstract]
Current assets	221,169	248,998
Non-current assets	293,409	310,975
Total assets	514,578	559,973
Current liabilities	131,664	127,292
Non-current liabilities	188,822	244,978
Equity	194,092	187,703
Total liabilities and equity	514,578	559,973
Revenue	298,731	327,351	368,586
Gross profit	46,717	50,371	60,873
Net income	$ 13,285	$ 14,581	21,871
Petroleum Air Services
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%	25.00%
Investment in unconsolidated affiliates	$ 6,286	$ 6,286
Cougar
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	40.00%	40.00%
Investment in unconsolidated affiliates	$ 54,009	$ 56,885
Business acquisition, percentage of voting interests acquired	25.00%
Income (Loss) from Equity Method Investments	$ (2,877)	$ (2,857)	(2,001)
Lider
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	41.90%	41.90%
Investment in unconsolidated affiliates	$ 62,267	$ 143,477
Business acquisition, percentage of voting interests acquired	20.00%
Income (Loss) from Equity Method Investments	$ 7,179	8,064	(116)
Other Unconsolidated Significant Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated affiliates	3,608	3,514
Income (Loss) from Equity Method Investments	$ (82)	$ (330)	$ 310