INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Examination [Line Items]
Effective income taxes	15.10%	16.20%	16.70%
Tax credits	$ 3,000	$ 2,900	$ 1,100
Accruals for uncertain tax positions	0	$ 0
Federal
Income Tax Examination [Line Items]
Operating loss carryforwards	$ 165,200
Operating loss carryforwards, limitations on use	operating loss carryforwards of approximately $165.2 million, of which approximately $144.4 million under pre-2018 law can be carried forward 20 years, and $20.8 million that can be carried forward indefinitely
State
Income Tax Examination [Line Items]
Operating loss carryforwards	$ 334,100
Operating loss carryforwards, limitations on use	operating loss carryforwards of approximately $334.1 million, of which approximately $226.1 million will begin to expire after 2026, and $108 million that can be carried forward indefinitely.
Operating loss carryforward subject to expiration	$ 226,100
Operating loss carryforward not subject to expiration	$ 108,000
Operating loss carryforwards expiration date	Dec. 31, 2026
Pre-2018 | Federal
Income Tax Examination [Line Items]
Tax carryforward	$ 144,400
Post-2018 | Federal
Income Tax Examination [Line Items]
Tax carryforward	$ 20,800