DEFERRED DRYDOCK COSTS, NET (Changes in Deferred Balances) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Deferred Drydock Costs [Roll Forward]
Balance at beginning of period			$ 8,802	$ 6,660	$ 6,660
Drydock costs accrued			4,789		5,531
Amortization of drydock costs	$ (873)	$ (754)	(1,631)	$ (1,607)	(3,104)
Unamortized dry-dock cost write-off for a retired vessel					(138)
Foreign currency translation adjustment			257		(147)
Balance at end of period	$ 12,217		$ 12,217		$ 8,802