Investments (Tables)

6 Months Ended

Mar. 31, 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:

	March 31, 2020
(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Commercial paper and corporate bonds	$	33,356	$	—	$	(166	)	$	33,190
Total	$	33,356	$	—	$	(166	)	$	33,190

	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