Marketable Securities (Details 1) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Feb. 29, 2020	Aug. 31, 2019
Summary of held to maturity securities [Abstract]
Amortized cost	$ 2,014	$ 4,135
Gross unrealized gains/losses	8	10
Estimated fair value	2,022	4,145
Short-term [Member] | Accrued interest [Member]
Summary of held to maturity securities [Abstract]
Amortized cost	16	32
Gross unrealized gains/losses
Estimated fair value	16	32
Long-term [Member]
Summary of held to maturity securities [Abstract]
Amortized cost	250	1,295
Gross unrealized gains/losses		4
Estimated fair value	250	1,299
Commercial bonds [Member] | Short-term [Member]
Summary of held to maturity securities [Abstract]
Amortized cost	1,748	2,808
Gross unrealized gains/losses	8	6
Estimated fair value	$ 1,756	$ 2,814