EQUITY AND CHANGES IN OTHER COMPREHENSIVE INCOME (LOSS) - Equity (Details) - USD ($)			1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 19, 2019	Jan. 25, 2019	Sep. 24, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Total equity				$ 173,544,000	$ 149,205,000	$ 173,544,000	$ 149,205,000	$ 167,255,000	$ 154,996,000	$ 144,642,000	$ 134,780,000
Common stock, dividends, declared (in dollars per share)	$ 0.14		$ 0.16
Cash dividend on common stock		$ 1,500,000		$ 1,724,000	1,496,000	4,962,000	3,778,000
Preferred stock dividends paid						$ 27,500
PDL LLC | Corporate Joint Venture
Class of Stock [Line Items]
Ownership percentage				51.00%		51.00%
Preferred Stock
Class of Stock [Line Items]
Total equity				$ 500,000	3,417,000	$ 500,000	3,417,000	550,000	1,224,000	9,195,000	15,971,000
Conversion of stock, shares converted						724,000
Common Stock
Class of Stock [Line Items]
Total equity				$ 1,105,000	$ 1,068,000	$ 1,105,000	$ 1,068,000	$ 1,105,000	$ 1,095,000	$ 996,000	$ 830,000
Shares issued upon conversion						90,532