REVENUE AND RECEIVABLES - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable
Gross accounts receivable	$ 131,400	$ 67,100
Allowance for credit loss	13,900	12,100
Customer receivable, current	4,145	1,227
Customer receivable - long term	39,652	9,614
FirstNet agreement
Accounts Receivable
Customer receivable	43,800	10,800
Customer receivable, current	4,100	1,200
Customer receivable - long term	$ 39,700	$ 9,600