CAPITAL STOCK - Completed public offerings ofcommon stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock Issued During Period Shares New Issues									100,828,173	13,019,240	14,377,000
Stock Issued During Period, Value, New Issues									$ 514,059	$ 71,050	$ 92,314
At the Market Offering Program [Member]
Weighted Average Price Received Per Share	$ 4.87	$ 4.94	$ 5.40	$ 5.10	$ 5.41	$ 5.15	$ 0	$ 6.23	$ 4.87	$ 5.41
Stock Issued During Period Shares New Issues	23,674,698	35,818,338	23,087,089	308,048	6,775,187	3,073,326	0	3,170,727
Stock Issued During Period, Value, New Issues	$ 115,398	$ 177,007	$ 124,746	$ 1,572	$ 36,037	$ 15,566	$ 0	$ 19,447
Follow-on Offering [Member]
Weighted Average Price Received Per Share				$ 5.31
Stock Issued During Period Shares New Issues				17,940,000
Stock Issued During Period, Value, New Issues				$ 95,336