Schedule of Amortized Cost and Fair Value of Cash Equivalents, Investments, and Restricted Cash and Investments with Contractual Maturities (Detail) $ in Thousands	Dec. 27, 2015 USD ($)
Fair Value Disclosures [Abstract]
Due in one year or less, cost	$ 2,260,834
Due after one year through five years, cost	1,837,148
Due in more than five years, cost	204,170
Cost, Total	4,302,152
Due in one year or less, estimated fair value	2,260,815
Due after one year through five years, estimated fair value	1,829,956
Due in more than five years, estimated fair value	202,794
Estimated fair value, Total	$ 4,293,565