RELATED PARTY TRANSACTIONS - Working Capital at Navig8 Pools (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) item	Dec. 31, 2017 USD ($)
Related party transactions
Working capital at Navig8 pools	$ 33,100	$ 26,100
Navig8 Pools
Related party transactions
Working capital at Navig8 pools	$ 33,100	26,100
VL8 Pool Inc. | VL8 Pool
Related party transactions
Revised operating capital to be provided to related party		1,000
V8 Pool Inc. | Suez8 Pool
Related party transactions
Revised operating capital to be provided to related party		900
V8 Pool Inc. | V8 Pool
Related party transactions
Revised operating capital to be provided to related party		$ 700
Gener8 Spyridon and Gener8 Ulysses | Navig8 Pools
Related party transactions
Number of Vessels Sold | item	2
Gener8 Spyridon | Navig8 Pools | Prepaid expenses and other current assets
Related party transactions
Working capital due from Navig8	$ 900
Gener8 Ulysses | Navig8 Pools | Prepaid expenses and other current assets
Related party transactions
Working capital due from Navig8	$ 1,000