REVENUE AND CONTRACT LIABILITY Sales Return Allowance (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Sales returns allowance [Abstract]
Sales Return, Reserve for Sales Returns, Current	$ 23,245	$ 19,190	$ 11,106
Sales Returns, Additions To Reserve For Sales Returns	130,225	204,810
Deductions From Sales Returns, Current	$ (126,170)	$ (196,726)