CAPITAL STOCK - Issuances of Common Stock (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Class A Common Stock [Member]
Class of Stock [Line Items]
Shares Sold to Employees	0	0	83,332	0
Total Shares Issued During Period	0	0	83,332	0
Class B Common Stock [Member]
Class of Stock [Line Items]
Total Shares Issued During Period	0	0	0	0
Class C Common Stock [Member]
Class of Stock [Line Items]
Total Shares Issued During Period	0	0	0	0