Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 20,477	$ 33,104
Available-for-sale investments:
Net unrealized gain (loss), net of tax of ($952) and $268 in 2020 and 2019, respectively	(3,861)	2,251
Reclassification of credit loss on investments	160	0
Reclassification of net realized (gain) loss into current operations	(1,850)	(40)
Net change related to available-for-sale investments	(5,551)	2,211
Foreign currency translation adjustments:
Foreign currency translation adjustments	(7,365)	218
Other comprehensive income (loss), net of tax	(12,916)	2,429
Total comprehensive income	$ 7,561	$ 35,533