SEGMENT REPORTING - Revenue and Assets (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax	$ 123,702	$ 111,739	$ 109,098	$ 110,905	$ 112,085	$ 115,616	$ 107,721	$ 103,300	$ 455,444	$ 438,722	$ 451,207
Long-Lived Assets	843,647				902,002				843,647	902,002	831,538
U.S
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax									122,256	123,508	132,288
Long-Lived Assets	308,138				297,084				308,138	297,084	234,514
Guyana
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax									103,071	105,290	102,056
Long-Lived Assets	141,487				145,079				141,487	145,079	151,084
U.S. Virgin Islands
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax									90,368	83,795	79,785
Long-Lived Assets	230,630				235,384				230,630	235,384	216,173
Bermuda
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax									103,471	104,760	103,281
Long-Lived Assets	116,346				128,208				116,346	128,208	137,992
Other Foreign Countries
Revenue and long lived assets
Revenue from Contract with Customer, Excluding Assessed Tax									36,278	21,369	33,797
Long-Lived Assets	$ 47,045				$ 96,247				$ 47,045	$ 96,247	$ 91,775