PORT PREFERRED STOCK (Schedule) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Issuance of common stock	$ 262	$ 835	$ 1,418
Other offering costs	$ (19)	$ (27)	(11)
Balance (in shares)	98,054,582	65,866,765
Balance	$ 277,388	$ 293,964	260,983
Balance	$ 519,712	$ 277,388	$ 293,964
Preferred Stock | Series A Preferred Stock
Class of Stock [Line Items]
Issuance of common stock (in shares)		15,000
Issuance of common stock		$ 15,000
Other offering costs		$ (91)
Balance (in shares)	15,000	15,000
Balance	$ 14,909
Dividends Available Upon Redemption	973
Dividends Paid	(748)
Balance	$ 15,134	$ 14,909
Preferred Stock | Series B Preferred Stock
Class of Stock [Line Items]
Issuance of common stock (in shares)		125
Issuance of common stock		$ 125
Other offering costs		$ (26)
Balance (in shares)	125	125
Balance	$ 99
Dividends Available Upon Redemption	16
Dividends Paid	(16)
Balance	$ 99	$ 99