pre_text: The following table summarizes the maturities of our available-for-sale debt investments as of July 27, 2019 (in millions): Actual maturities may differ from the contractual maturities because borrowers may have the right to call or prepay certain obligations.
table: Amortized Cost Fair Value
table: Within 1 year $6,322 $6,324
table: After 1 year through 5 years 12,191 12,218
table: After 5 years through 10 years 1,643 1,687
table: After 10 years 9 10
table: Mortgage-backed securities with no single maturity 1,425 1,421
table: Total $21,590 $21,660
question: Analyse this data from a financial earnings document. What was the difference between the total amortized cost and total fair value?