Investments - Maturities of Available-for-sale and Held-to-maturity Securities (Details) $ in Millions	Nov. 20, 2016 USD ($)
Available-for-sale, Cost Basis
Due in one year or less	$ 181
Due after one year through five years	796
Due after five years	70
Available-for-sale, cost basis, total	1,047
Available-for-sale, Fair Value
Due in one year or less	181
Due after one year through five years	795
Due after five years	69
Available-for-sale, recorded basis, total	1,045
Held-to-maturity
Due in one year or less	266
Due after one year through five years	0
Due after five years	0
Held-to-maturity, cost basis, total	$ 266