PORT PREFERRED STOCK (Schedule) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Issuance of common stock	$ 835	$ 1,418	$ 8,666
Other offering costs	$ (27)	$ (11)	(8)
Balance (in shares)	65,866,765	66,822,861
Balance, December 31, 2019	$ 277,388	$ 293,964	$ 260,983	$ 295,550
Preferred Stock | Series A Prefered 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
Balance, December 31, 2019	$ 14,909
Preferred Stock | Series B Prefered 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
Balance, December 31, 2019	$ 99