Stockholders' Equity - Reclassified from AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Amounts Reclassified from AOCI
Income (loss) before income taxes	$ 14,722	$ 17,830	$ 36,756	$ 31,286
Provision (benefit) for income taxes	(442)	(1,261)	3,929	709
Net income	14,280	$ 16,569	40,685	31,995
Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Income (loss) before income taxes	(33)		(82)	1,808
Provision (benefit) for income taxes	7		17	(633)
Net income	(26)		(65)	1,175
Losses on available-for-sales securities | Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Interest income and other, net			(49)
Gains (losses) on cash flow hedges | Reclassifications From Accumulated Other Comprehensive Income (Loss)
Amounts Reclassified from AOCI
Interest expense	$ (33)		$ (33)	$ 1,808