Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 99,318	$ 81,157	$ 247,352	$ 218,543
Other comprehensive income (loss), net of tax effects:
Foreign currency translation adjustments	(9,186)	3,549	(16,237)	13,803
Changes in unrealized holding gains or losses on available-for-sale securities, net of reclassification adjustment for realized gains and losses	0	1,000	0	1,248
Changes in defined benefit plan liabilities	7	19	154	89
Total other comprehensive income (loss), net of tax effects	(9,179)	4,568	(16,083)	15,140
Comprehensive income	$ 90,139	$ 85,725	$ 231,269	$ 233,683