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SUBSEQUENT EVENTS (Details) $ / shares in Units, $ in Thousands																			2 Months Ended	3 Months Ended						12 Months Ended
	Feb. 24, 2021 USD ($) $ / shares	Feb. 23, 2021 $ / shares shares	Feb. 18, 2021 USD ($)	Jan. 25, 2021 USD ($)	Jan. 22, 2021 USD ($)	Jan. 15, 2021 USD ($)	Jan. 04, 2021 USD ($)	Dec. 17, 2020 item	Nov. 27, 2020 USD ($)	Nov. 03, 2020 USD ($)	Jul. 15, 2020 shares	Feb. 25, 2020 $ / shares shares	Feb. 03, 2020 USD ($)	May 15, 2019 shares	Mar. 04, 2019 $ / shares shares	May 31, 2018	May 15, 2018 shares	Feb. 27, 2018 $ / shares shares	Feb. 24, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) $ / shares	Sep. 30, 2020 $ / shares	Jun. 30, 2020 $ / shares	Mar. 31, 2020 $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Subsequent Events
Dividends declared per share of common stock \| $ / shares																					$ 0.02	$ 0.02	$ 0.02	$ 0.175	$ 500	$ 0.235	$ 0.50
Loss on disposal of vessels																										$ 1,855	$ 168	$ (3,513)
Restricted cash, current																					$ 35,492				$ 6,045	$ 35,492	$ 6,045
Baltic Panther
Subsequent Events
Sale of assets										$ 7,510
Broker commission (as a percent)										3.00%
Baltic Hare
Subsequent Events
Sale of assets									$ 7,750
Broker commission (as a percent)									2.00%
Genco Charger
Subsequent Events
Sale of assets													$ 5,150
Broker commission (as a percent)													1.00%
Secured Debt \| $495 Million Credit Facility
Subsequent Events
Collateral vessel replacement period																120 days
2015 EIP Plan \| Restricted Stock Units
Subsequent Events
Granted (in shares) \| shares											42,642	173,749		29,580	106,079		14,268	37,436								221,903	140,914	51,704
Vesting period of awards																										3 years
2015 EIP Plan \| Stock Options
Subsequent Events
Options to purchase (in shares) \| shares												344,568			240,540			122,608								344,568	240,540	122,608
Exercise price \| $ / shares												$ 7.06			$ 8.065			$ 13.365								$ 7.06	$ 8.33	$ 13.69
Vesting percentage of awards												33.33%			33.33%			33.33%
Vesting period of awards												3 years			3 years			3 years
Subsequent Event
Subsequent Events
Dividends declared per share of common stock \| $ / shares	$ 0.02
Aggregate amount of dividend	$ 800																		$ 800
Subsequent Event \| Baltic Leopard
Subsequent Events
Sale of assets				$ 8,000
Broker commission (as a percent)				2.00%
Subsequent Event \| Genco Lorraine
Subsequent Events
Sale of assets					$ 7,950
Broker commission (as a percent)					2.50%
Subsequent Event \| Baltic Panther
Subsequent Events
Sale of assets							$ 7,510
Broker commission (as a percent)							3.00%
Subsequent Event \| Baltic Hare
Subsequent Events
Sale of assets						$ 7,750
Broker commission (as a percent)						2.00%
Subsequent Event \| Baltic Cougar
Subsequent Events
Sale of assets	$ 7,600
Broker commission (as a percent)	3.00%
Subsequent Event \| Secured Debt \| $495 Million Credit Facility \| Baltic Panther
Subsequent Events
Restricted cash, current							$ 4,515
Subsequent Event \| Secured Debt \| $495 Million Credit Facility \| Baltic Hare
Subsequent Events
Restricted cash, current						$ 4,806
Subsequent Event \| Secured Debt \| $495 Million Credit Facility \| Baltic Cougar
Subsequent Events
Restricted cash, current	$ 4,515																		$ 4,515
Subsequent Event \| Secured Debt \| $495 Million Credit Facility \| Baltic Panther Baltic Hare and Baltic Cougar
Subsequent Events
Period for which sales proceeds from vessels will remain as restricted cash																			360 days
Collateral vessel replacement period																			360 days
Subsequent Event \| Secured Debt \| $495 Million Credit Facility \| Genco Charger
Subsequent Events
Vessel sale proceeds utilized as a loan repayment			$ 3,471
Subsequent Event \| 2015 EIP Plan \| Restricted Stock Units
Subsequent Events
Granted (in shares) \| shares		103,599
Subsequent Event \| 2015 EIP Plan \| Stock Options
Subsequent Events
Options to purchase (in shares) \| shares		118,552
Exercise price \| $ / shares		$ 9.91
Subsequent Event \| 2015 EIP Plan \| RSUs and Stock Options
Subsequent Events
Vesting percentage of awards		33.33%
Vesting period of awards		3 years
Subsequent Event \| Forecast \| Baltic Panther Baltic Hare and Baltic Cougar \| Minimum
Subsequent Events
Loss on disposal of vessels																				$ 500
Subsequent Event \| Forecast \| Baltic Panther Baltic Hare and Baltic Cougar \| Maximum
Subsequent Events
Loss on disposal of vessels																				$ 700
Agreement To Exchange Vessels \| Ultramax Vessels
Subsequent Events
Number of vessels to be exchanged \| item								3
Agreement To Exchange Vessels \| Handysize Vessels
Subsequent Events
Number of vessels to be exchanged \| item								6
Broker commission (as a percent)								1.00%