SUBSEQUENT EVENTS - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended
	May 03, 2019	Mar. 31, 2019	Mar. 31, 2018
SUBSEQUENT EVENTS
Stock Repurchased During Period, Value		$ 2,448,000	$ 2,951,000
Repurchase Of Common Stock Price Per Share		$ 2.24
Common Stock Class D [Member]
SUBSEQUENT EVENTS
Stock Repurchased During Period, Shares			1,568,246
Stock Repurchased During Period, Value		$ 1,000	$ 1,000
Subsequent Event [Member] | Common Stock Class D [Member]
SUBSEQUENT EVENTS
Stock Repurchased During Period, Shares	22,000
Stock Repurchased During Period, Value	$ 44,000
Repurchase Of Common Stock Price Per Share	$ 2.01
Subsequent Event [Member] | Common Stock Class D [Member] | Stock Vest Tax Repurchase [Member]
SUBSEQUENT EVENTS
Stock Repurchased During Period, Shares	6,368
Stock Repurchased During Period, Value	$ 12,000
Repurchase Of Common Stock Price Per Share	$ 1.98