REVENUE AND CONTRACT LIABILITY Sales Return Allowance (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Sales returns allowance [Abstract]
Sales Return, Reserve for Sales Returns, Current	$ 18,657	$ 11,107	$ 15,261
Sales Returns, Additions To Reserve For Sales Returns	92,510	117,040
Deductions From Sales Returns, Current	$ (84,960)	$ (121,194)