REDEEMABLE PREFERRED STOCK - Dividends (Details) - USD ($) $ in Thousands									1 Months Ended	12 Months Ended
	Dec. 04, 2018	Aug. 22, 2018	Jun. 04, 2018	Mar. 06, 2018	Dec. 06, 2017	Sep. 07, 2017	Jun. 12, 2017	Mar. 08, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Cash Dividends Declared											$ 490	$ 9
Redeemable preferred stock dividends accumulated										$ (1,436)	1,436	$ 0
Series A Preferred Stock
Class of Stock [Line Items]
Number of Shares (in shares)	2,847,150	2,457,119	2,149,863	1,674,841	1,285,304	568,921	308,775	144,698
Cash Dividends Declared	$ 890	$ 769	$ 662	$ 493	$ 249	$ 138	$ 72	$ 31		2,814
Series L Preferred Stock
Class of Stock [Line Items]
Number of Shares (in shares)	8,080,740											0
Cash Dividends Declared	$ 14,045									$ 14,045
Redeemable preferred stock prorated cash dividend									$ 1,436
Redeemable preferred stock dividends accumulated											$ 1,436