Contractual Maturity of Available-for-sale Debt Securities (Detail) $ in Millions	Sep. 30, 2018 USD ($)
Amortized Cost
Due within one year	$ 3,443
Due after 1 year through 5 years	4,089
Due after 5 years through 10 years	0
Due after 10 years	0
Total	7,532
Fair Value
Due within one year	3,434
Due after 1 year through 5 years	4,082
Due after 5 years through 10 years	0
Due after 10 years	0
Total	$ 7,516

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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