Amortized Cost and Fair Value of Available for Sale Securities by Expected Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Cost
Due in one year or less	$ 667,148	$ 917,576
Due after one year through five years	2,771,861	2,794,099
Due after five years through ten years	276,032	205,792
Due after ten years	12,797	9,230
Total	3,727,838	3,926,697
Fair Value
Due in one year or less	665,338	915,579
Due after one year through five years	2,701,701	2,757,504
Due after five years through ten years	272,281	203,533
Due after ten years	12,909	9,515
Total	$ 3,652,229	$ 3,886,131