Cash, Cash Equivalents, and Investments - Components of Cash, Cash Equivalents, and Investments (Detail) - USD ($) $ in Thousands	Jul. 05, 2015	Dec. 31, 2014	Jun. 29, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cash	$ 55,379	$ 54,917
Money market instruments	6,312	777
Cash and cash equivalents	61,691	55,694	$ 40,172	$ 40,644
Short-term investments	223,464	90,456
Limited partnership interest	1,956	1,956
Long-term investments	233,752	400,845
Total	518,907	546,995
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	75,431	0
Long-term investments	6,505	90,412
Euro Liquidity Fund
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	63,163	48,235
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	39,071	30,889
Long-term investments	175,912	216,294
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	37,894	1,311
Long-term investments	38,211	62,556
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	6,095	0
Long-term investments	2,010	13,461
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	1,810	1,237
Long-term investments	4,874	6,600
Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	0	6,883
Long-term investments	4,284	9,566
Supranational Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 0	$ 1,901