Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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INVESTMENTS IN SECURITIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 24, 2017	Sep. 30, 2018	Sep. 24, 2017	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Gross realized gains	$ 2,500	$ 2,000	$ 5,400	$ 3,100
Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	253,500		253,500		$ 330,456
Fair Value	253,500		253,500		330,456
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	32,273		32,273		942
Fair Value	$ 32,273		$ 32,273		$ 942