INCOME TAXES (Provision for Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract]
Domestic	$ 168,117	$ 156,571	$ 115,070
Foreign	6,433	(8,332)	(20,588)
Income before provision for income taxes	174,550	148,239	94,482
Current:
Federal	33,327	20,482	(7,677)
State	14,575	14,564	12,653
Foreign	1,559	7,448	4,781
Current income taxes	49,461	42,494	9,757
Deferred
Federal	(965)	7,933	19,899
State	(2,506)	550	(1,205)
Foreign	(6,277)	(478)	395
Deferred income taxes	(9,748)	8,005	19,089
Provision for income taxes	$ 39,713	$ 50,499	$ 28,846
Effective tax rate	22.80%	34.10%	30.50%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax expense at US statutory rate	$ 36,655	$ 31,130	$ 19,841
State income taxes, net of federal benefit	9,837	10,597	8,711
Foreign rate differential	1,256	276	(1,124)
Valuation allowance	(11,339)	4,459	10,466
Uncertain tax position interest and penalties	(712)	474	(1,806)
Tax credits	2,039	(50)	(9,799)
Non-deductible compensation	1,406	1,922	1,813
Other	571	1,691	1,032
Adjustment for Tax Cuts and Jobs Act	0	0	(288)
Provision for income taxes	$ 39,713	$ 50,499	$ 28,846