Retirement and Other Benefit Plans - Schedule Of Reconciliation Of Fair Value Of Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Retirement and Other Benefit Plans
Fair value of plan assets at beginning of year	$ 73,300	$ 65,000
Actual return on plan assets	5,900	2,700
Employer contributions	2,700	10,200
Gross benefits paid	(4,700)	(4,600)
Settlements	0	0
Fair value of plan assets at end of year	$ 77,200	$ 73,300