Debt Investment Maturities (Detail) $ in Millions	Dec. 31, 2019 USD ($)
Cost Basis
Due in one year or less	$ 40,357
Due after one year through five years	48,195
Due after five years through 10 years	37,123
Due after 10 years	1,595
Debt investments, Cost Basis	127,270
Estimated Fair Value
Due in one year or less	40,381
Due after one year through five years	49,166
Due after five years through 10 years	38,138
Due after 10 years	1,652
Total	$ 129,337