Investments (Tables)

9 Months Ended

Jun. 30, 2020

Investments Debt And Equity Securities [Abstract]

Amortized Cost, Unrealized Holding Gains and (Losses) and Fair Value of Available-for-sale Securities

The amortized cost, unrealized holding gains and losses, and fair value of available-for-sale securities were as follows:

	June 30, 2020
(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Commercial paper and corporate bonds	$	24,161	$	17	$	—	$	24,178
Total	$	24,161	$	17	$	—	$	24,178

	September 30, 2019
(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Commercial paper and corporate bonds	$	24,918	$	13	$	—	$	24,931
Total	$	24,918	$	13	$	—	$	24,931