Net Carrying Values of Debt Securities by Contractual Maturity (Detail) $ in Thousands	Aug. 31, 2018 USD ($)
Available-for-Sale Securities, amortized cost
Less than one year, amortized cost	$ 7,114
One year through five years, amortized cost	13,180
Six years through ten years, amortized cost	3,542
After ten years, amortized cost	1,065
Available-for-sale Debt Securities, Amortized Cost Basis, Total	24,901
Available-for-Sale Securities, fair value
Less than one year, fair value	7,072
One year through five years, fair value	12,898
Six years through ten years, fair value	3,412
After ten years, fair value	1,096
Marketable debt securities, carrying value	$ 24,478

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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