INCOME TAXES - Additional Information (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 27, 2018	Oct. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Long-term asset			$ 64,526	$ 604
Tax expense			5,471	45,652	$ 20,528
Withholding and interest for licencing and royalty payments		$ 13,200
Withholding and interest for licencing and royalty payments period		3 years
Current income tax expense			$ 8,677	15,406	12,902
State and foreign income tax returns subject to examination period minimum (in years)			3 years
State and foreign income tax returns subject to examination period maximum (in years)			4 years
Korean Government [Member]
Income Taxes [Line Items]
Estimated settlement amounts due (refunds) from withholding taxes			$ (36,900)
U.S.Federal Government [Member]
Income Taxes [Line Items]
Estimated settlement amounts due (refunds) from withholding taxes			16,200
South Korea [Member]
Income Taxes [Line Items]
Current income tax expense			14,900	$ 17,600	$ 14,400
Reduction of Korean Withholding Taxes [Member]
Income Taxes [Line Items]
Reduction of deferred tax asset for foreign tax credits and R&D			$ 20,700
Allocation of Withholding to Non-Korean Patents [Member]
Income Taxes [Line Items]
Long-term asset	$ 13,600
Allocation of Withholding to Korean Patents [Member]
Income Taxes [Line Items]
Tax expense	$ 1,300