COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands		6 Months Ended	12 Months Ended
	Dec. 21, 2018 item	Dec. 31, 2018 USD ($) item	Dec. 31, 2019 USD ($) item	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Feb. 28, 2019 USD ($)
Purchase commitment
Vessel assets			$ 1,273,861	$ 1,121,561
Secured Debt | $495 Million Credit Facility
Purchase commitment
Maximum borrowing capacity			495,000	495,000	$ 495,000	$ 495,000
Purchase Agreements for BWTS
Purchase commitment
Number of vessels to receive ballast water treatments systems | item		42
Vessel assets			$ 12,783	14,225
Purchase Agreement of BWTS for Capesize Vessels
Purchase commitment
BWTS purchase price		$ 900
Purchase Agreement of BWTS for Supramax Vessels
Purchase commitment
BWTS purchase price		600
Purchase Agreement of BWTS for Handysize Vessels
Purchase commitment
BWTS purchase price		$ 500
Scrubber Installation Agreements
Purchase commitment
Number of Capesize vessels to receive scrubber installations | item	17		16
Vessel assets			$ 41,270	$ 42,477