Investments (Tables)

3 Months Ended

Dec. 31, 2019

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:

	December 31, 2019
(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
Commercial paper and corporate bonds	$	39,251	$	5	$	—	$	39,256
Total	$	39,251	$	5	$	—	$	39,256

	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