REVENUE AND CONTRACT LIABILITY Unearned Revenue (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contract with Customer, Liability	$ 89,705	$ 41,821	$ 50,578
Increase (Decrease) in Contract with Customer, Liability	80,287	36,622
Contract with Customer, Liability, Revenue Recognized	$ (32,403)	$ (45,379)