VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation and qualifying accounts [Roll forward]
Net operating loss carryforwards valuation allowance	$ 329	$ 71,782
Valuation allowance expense (benefit) from Tax Cuts and Jobs Act		(112,355)
Federal and state
Valuation and qualifying accounts [Roll forward]
Net operating loss carryforwards valuation allowance	(5,919)	294,568	$ 128,931
Tax credit valuation allowance	49,800	49,500
Valuation allowance expense (benefit) from Tax Cuts and Jobs Act	6,042	(222,786)
Federal
Valuation and qualifying accounts [Roll forward]
Tax credit valuation allowance	207		13,931
Allowance for Doubtful Accounts
Valuation and qualifying accounts [Roll forward]
Balance at beginning of period	23,112	27,044	26,470
Charged to costs and expenses	17,597	25,370	30,632
Charged to other accounts	7,153	555	2,680
Deductions	(23,109)	(29,857)	(32,738)
Balance at end of period	24,753	23,112	27,044
Deferred Tax Valuation Allowance
Valuation and qualifying accounts [Roll forward]
Balance at beginning of period	336,087	264,305	121,602
Charged to costs and expenses	330	71,782	142,862
Charged to other accounts	0	0	0
Deductions	0	0	(159)
Balance at end of period	$ 336,417	$ 336,087	$ 264,305